fixing numbering in project-layout and source docs for consistency.

docs/project-layout.md

@@ -60,14 +60,14 @@ and talk through which code gets run in order.
 
 ## How to add a new command
 
-0. First, check on our issue tracker to verify that our team had approved the plans for a new command.
-1. Create a package for the new command, e.g. for a new command `gh boom` create the following directory
+1. First, check on our issue tracker to verify that our team had approved the plans for a new command.
+2. Create a package for the new command, e.g. for a new command `gh boom` create the following directory
    structure: `pkg/cmd/boom/`
-2. The new package should expose a method, e.g. `NewCmdBoom()`, that accepts a `*cmdutil.Factory` type and
+3. The new package should expose a method, e.g. `NewCmdBoom()`, that accepts a `*cmdutil.Factory` type and
    returns a `*cobra.Command`.
    * Any logic specific to this command should be kept within the command's package and not added to any
      "global" packages like `api` or `utils`.
-3. Use the method from the previous step to generate the command and add it to the command tree, typically
+4. Use the method from the previous step to generate the command and add it to the command tree, typically
    somewhere in the `NewCmdRoot()` method.
 
 ## How to write tests

docs/source.md

@@ -1,21 +1,21 @@
 # Installation from source
 
-0. Verify that you have Go 1.16+ installed
+1. Verify that you have Go 1.16+ installed
 
    ```sh
    $ go version
    ```
 
    If `go` is not installed, follow instructions on [the Go website](https://golang.org/doc/install).
 
-1. Clone this repository
+2. Clone this repository
 
    ```sh
    $ git clone https://github.com/cli/cli.git gh-cli
    $ cd gh-cli
    ```
 
-2. Build and install
+3. Build and install
 
    #### Unix-like systems
    ```sh
@@ -33,7 +33,7 @@
    ```
    There is no install step available on Windows.
 
-3. Run `gh version` to check if it worked.
+4. Run `gh version` to check if it worked.
 
    #### Windows
    Run `bin\gh version` to check if it worked.