chore: fix filename in command (#1064)

book/src/writing-apps/write-program.md

@@ -22,16 +22,18 @@ More examples of guest programs can be found in the [benchmarks/programs](https:
 
 Although it's usually ok to use std (like in quickstart), not all std functionalities are supported (e.g., randomness). There might be unexpected runtime errors if one uses std, so it is recommended you develop no_std libraries if possible to reduce surprises.
 Even without std, `assert!` and `panic!` can work as normal. To use `std` features, one should add the following to `Cargo.toml` feature sections:
+
 ```toml
 [features]
 std = ["openvm/std"]
-``` 
+```
 
 ### Building and running
 
-*TODO*: point to CLI installation instructions
+_TODO_: point to CLI installation instructions
 
 First we need to build the program targeting the OpenVM runtime, and that requires some configuration. Put the following in `openvm.toml`:
+
 ```toml
 [app_fri_params]
 log_blowup = 2
@@ -53,7 +55,7 @@ cargo openvm build --transpile --transpiler-config openvm.toml --transpile-to ou
 Next we can keygen the generate the proving and verifying keys:
 
 ```bash
-cargo openvm keygen --config app_config.toml --output outputs/pk --vk-output outputs/vk
+cargo openvm keygen --config openvm.toml --output outputs/pk --vk-output outputs/vk
 ```
 
 Now, to prove the program some input is needed. The input parameter is either a hex string or a file path. So for example if we want to compute the 10th fibonacci number, we can run:
@@ -70,6 +72,7 @@ No errors should be returned, and the proof should be correctly verified.
 The program can take input from stdin, with some functions provided by `openvm::io`.
 
 `openvm::io::read` takes from stdin and deserializes it into a generic type `T`, so one should specify the type when calling it:
+
 ```rust
 let n: u64 = read();
 ```