website/docs: Update documentation to reflect new common custom types (…

…#811)

* initial changes to custom type docs

* reference new types

website/docs/plugin/framework/handling-data/attributes.mdx

@@ -577,3 +577,6 @@ You may want to build your own attribute value and type implementations to allow
 
 Refer to [Custom Types](/terraform/plugin/framework/handling-data/custom-types) for further details on creating provider-defined types and values.
 
+## Common Custom Types and Values
+
+A collection of Go modules have been created with attribute value and type implementations for common use cases, such as normalized JSON strings, IPv4/IPv6 addresses, and RFC3339 time strings. Refer to [Common Custom Types](/terraform/plugin/framework/handling-data/custom-types#common-custom-types) for further details.

website/docs/plugin/framework/handling-data/custom-types.mdx

@@ -15,10 +15,19 @@ Supported behaviors for custom types include:
 
 ## Example Use Cases
 
-- Encoded values, such as JSON or YAML string.
-- Networking values, such as an IPv4 address string.
-- Time values, such as an RFC3339 string.
+- Encoded values, such as an XML or YAML string.
 - Provider-specific values, such as an AWS ARN or AzureRM location string.
+- Networking values, such as a MAC address.
+- Time values, such as an ISO 8601 string.
+
+## Common Custom Types
+The following Go modules contain custom type implementations covering common use cases with validation and semantic equality logic (where appropriate).
+- [`terraform-plugin-framework-jsontypes`](https://pkg.go.dev/github.com/hashicorp/terraform-plugin-framework-jsontypes)
+    - JSON strings (both normalized and exact matching)
+- [`terraform-plugin-framework-nettypes`](https://pkg.go.dev/github.com/hashicorp/terraform-plugin-framework-nettypes)
+    - IPv4/IPv6 addresses and CIDRs
+- [`terraform-plugin-framework-timetypes`](https://pkg.go.dev/github.com/hashicorp/terraform-plugin-framework-timetypes)
+    - Timestamps (such as RFC3339)
 
 ## Concepts
 
@@ -96,6 +105,8 @@ It is recommended to use Go type embedding of the base type to simplify the impl
 - `ValueFromTerraform(context.Context, tftypes.Value) (attr.Value, error)`
 - `ValueType(context.Context) attr.Value`
 - `String() string`
+- `ValueFrom{TYPE}(context.Context, basetypes.{TYPE}Value) (basetypes.{TYPE}Valuable, diag.Diagnostics)`
+    - This method signature is different for each `*Typable` custom schema type interface listed above, for example `basetypes.StringTypable` is defined as [`ValueFromString`](https://pkg.go.dev/github.com/hashicorp/terraform-plugin-framework/types/basetypes#StringTypable)
 
 In this example, the `basetypes.StringTypable` interface is implemented to create a custom string type with an associated [value type](#value-type):
 
@@ -196,6 +207,14 @@ It is recommended to use Go type embedding of the base type to simplify the impl
 - `Equal(attr.Value) bool`
 - `Type(context.Context) attr.Type`
 
+<Note>
+
+The overridden `Equal(attr.Value) bool` method should not contain [Semantic Equality](#semantic-equality) logic. `Equal` should only check the type of `attr.Value` and the underlying base value.
+
+An example of this can be found below with the `CustomStringValue` implementation.
+
+</Note>
+
 In this example, the `basetypes.StringValuable` interface is implemented to create a custom string value type with an associated [schema type](#schema-type):
 
 ```go