Feature/sg 907 add yaml explanation (#1422)

* start

* draft

documentation/source/LRScheduling.md

@@ -20,26 +20,44 @@ Learning rate scheduling type is controlled by the training parameter `lr_mode`.
 For example, the training code below will start with an initial learning rate of 0.1 and decay by 0.1 at epochs 100,150 and 200:
 
 ```python
-
 from super_gradients.training import Trainer
-...
+
 
 trainer = Trainer("my_custom_scheduler_training_experiment")
 
 train_dataloader = ...
 valid_dataloader = ...
 model = ...
-train_params = {...
-                "initial_lr": 0.1,
-                "lr_mode":"step",
-                "lr_updates": [100, 150, 200],
-                "lr_decay_factor": 0.1,
-                ...}
+train_params = {
+    "initial_lr": 0.1,
+    "lr_mode":"step",
+    "lr_updates": [100, 150, 200],
+    "lr_decay_factor": 0.1,
+    ...,
+}
 
 trainer.train(model=model, training_params=train_params, train_loader=train_dataloader, valid_loader=valid_dataloader)
-
 ```
 
+<details>
+<summary>Equivalent in a <code>.yaml</code> configuration file:</summary>
+
+```yaml
+training_hyperparams:
+    initial_lr: 0.1
+    lr_mode: step
+    user_lr_updates:
+      - 100
+      - 150
+      - 200
+    lr_decay_factor: 0.1
+    ...
+
+...
+```
+</details>
+
+
 ## Using Custom LR Schedulers
 
 Prerequisites: [phase callbacks](PhaseCallbacks.md), [training with configuration files](configuration_files.md).
@@ -182,26 +200,49 @@ from myscheduler import UserStepLRCallback # triggers registry, now we can pass
 
 And finally, use your new scheduler just as any other one supported by SG.
 ```python
-
-
 trainer = Trainer("my_custom_scheduler_training_experiment")
 
+# The following code sections marked with '...' are placeholders 
+# indicating additional necessary code that is not shown for simplicity.
 train_dataloader = ...
 valid_dataloader = ...
 model = ...
-train_params = {...
-                "initial_lr": 0.1,
-                "lr_mode": "user_step",
-                "user_lr_updates": [100, 150, 200], # WILL BE PASSED TO UserStepLRCallback CONSTRUCTOR
-                "user_lr_decay_factors": [0.1, 0.01, 0.001] # WILL BE PASSED TO UserStepLRCallback CONSTRUCTOR
-                ...}
+
+train_params = {
+    "initial_lr": 0.1,
+    "lr_mode": "user_step",
+    "user_lr_updates": [100, 150, 200], # WILL BE PASSED TO UserStepLRCallback CONSTRUCTOR
+    "user_lr_decay_factors": [0.1, 0.01, 0.001], # WILL BE PASSED TO UserStepLRCallback CONSTRUCTOR
+    ...
+}
 
 trainer.train(model=model, training_params=train_params, train_loader=train_dataloader, valid_loader=valid_dataloader)
-
 ```
 
 Note that internally, Trainer unpacks [training_params to the scheduler callback constructor](https://github.com/Deci-AI/super-gradients/blob/537a0f0afe7bcf28d331fe2c0fa797fa10f54b99/src/super_gradients/training/sg_trainer/sg_trainer.py#L1078), so we pass scheduler related parameters through training_params as well.
 
+
+<details>
+<summary>Equivalent in a <code>.yaml</code> configuration file:</summary>
+
+```yaml
+training_hyperparams:
+    initial_lr: 0.1
+    lr_mode: user_step
+    user_lr_updates: # WILL BE PASSED TO UserStepLRCallback CONSTRUCTOR
+      - 100
+      - 150
+      - 200
+    user_lr_decay_factors: # WILL BE PASSED TO UserStepLRCallback CONSTRUCTOR
+      - 0.1
+      - 0.01
+      - 0.001
+    ...
+
+...
+```
+</details>
+
 ### Using PyTorchs Native LR Schedulers (torch.optim.lr_scheduler)
 
 PyTorch offers a [wide variety of learning rate schedulers](https://pytorch.org/docs/stable/optim.html#how-to-adjust-learning-rate).
@@ -238,11 +279,15 @@ From `Trainer.train(...)` docs:
                     train_epoch(...)
                     scheduler.step()
                     ....
-For example:
+
+### Examples
+Using `StepLR`
 
 ```python
-...
 trainer = Trainer("torch_Scheduler_example")
+
+# The following code sections marked with '...' are placeholders 
+# indicating additional necessary code that is not shown for simplicity.
 train_dataloader = ...
 valid_dataloader = ...
 model = ...
@@ -260,13 +305,52 @@ train_params = {
     "valid_metrics_list": [Accuracy()],
     "metric_to_watch": "Accuracy",
     "greater_metric_to_watch_is_better": True,
-        }
+}
 trainer.train(model=model, training_params=train_params, train_loader=dataloader, valid_loader=dataloader)
 ```
 
-And as stated above, for ReduceLROnPlateau we need to pass a "metric_name", which follows the same
-rules as the training parameter "metric_to_watch"(see [metrics guide](Metrics.md) when not familiar).
-For example:
+<details>
+<summary>Equivalent in a <code>.yaml</code> configuration file:</summary>
+
+```yaml
+training_hyperparams:
+    # Setting up LR Scheduler
+    lr_mode:
+      StepLR:
+        gamma: 0.1
+        step_size: 1
+        phase: TRAIN_EPOCH_END
+
+    # Setting up other parameters
+    max_epochs: 2
+    lr_warmup_epochs: 0
+    initial_lr: 0.1
+    loss: CrossEntropyLoss
+    optimizer: SGD
+    criterion_params: {}
+    optimizer_params:
+      weight_decay: 1e-4
+      momentum: 0.9
+    train_metrics_list:
+      - Accuracy
+    valid_metrics_list:
+      - Accuracy
+    metric_to_watch: Accuracy
+    greater_metric_to_watch_is_better: true
+
+...
+```
+</details>
+
+
+**Using `ReduceLROnPlateau`**
+
+If you choose to use `ReduceLROnPlateau` as the learning rate scheduler, you need to specify a `metric_name`. 
+This parameter follows the same guidelines as `metric_to_watch`. 
+
+For an in-depth understanding of these metrics, 
+see the [metrics guide](Metrics.md).
+
 
 ```python
 trainer = Trainer("torch_ROP_Scheduler_example")
@@ -290,8 +374,41 @@ train_params = {
     "greater_metric_to_watch_is_better": True,
 }
 trainer.train(model=model, training_params=train_params, train_loader=dataloader, valid_loader=dataloader)
-
 ```
 
 The scheduler's `state_dict` is saved under `torch_scheduler_state_dict` entry inside the checkpoint during training,
 allowing us to resume from the same state of the scheduling.
+
+<details>
+<summary>Equivalent in a <code>.yaml</code> configuration file:</summary>
+
+```yaml
+training_hyperparams:
+    # Setting up LR Scheduler
+    lr_mode:
+      ReduceLROnPlateau:
+        patience: 0
+        phase: TRAIN_EPOCH_END
+        metric_name: DummyMetric
+
+    # Setting up other parameters
+    max_epochs: 2
+    lr_decay_factor: 0.1
+    lr_warmup_epochs: 0
+    initial_lr: 0.1
+    loss: CrossEntropyLoss
+    optimizer: SGD
+    criterion_params: {}
+    optimizer_params:
+      weight_decay: 1e-4
+      momentum: 0.9
+    train_metrics_list:
+      - Accuracy
+    valid_metrics_list:
+      - Accuracy
+    metric_to_watch: DummyMetric
+    greater_metric_to_watch_is_better: true
+
+...
+```
+</details>