Merge pull request #15652 from andy9a9/docs/tap

docs: Add info about tap creation

docs/How-To-Open-a-Homebrew-Pull-Request.md

@@ -36,13 +36,19 @@ The type of change you want to make influences which of Homebrew's main reposito
 
 1. [Fork the Homebrew/homebrew-core repository on GitHub](https://github.com/Homebrew/homebrew-core/fork).
  * This creates a personal remote repository that you can push to. This is needed because only Homebrew maintainers have push access to the main repositories.
-2. Change to the directory containing Homebrew formulae:
+2. Download a local clone ("tap") the repository of core Homebrew formulae:
+
+ ```sh
+ brew tap --force homebrew/core
+ ```
+
+3. Change to the directory containing Homebrew formulae:
 
  ```sh
  cd "$(brew --repository homebrew/core)"
  ```
 
-3. Add your pushable forked repository as a new remote:
+4. Add your pushable forked repository as a new remote:
 
  ```sh
  git remote add <YOUR_USERNAME> https://github.com/<YOUR_USERNAME>/homebrew-core.git
@@ -54,13 +60,19 @@ The type of change you want to make influences which of Homebrew's main reposito
 
 1. [Fork the Homebrew/homebrew-cask repository on GitHub](https://github.com/Homebrew/homebrew-cask/fork).
  * This creates a personal remote repository that you can push to. This is needed because only Homebrew maintainers have push access to the main repositories.
-2. Change to the directory containing Homebrew casks:
+2. Download a local clone ("tap") the repository of core Homebrew casks:
+
+ ```sh
+ brew tap --force homebrew/cask
+ ```
+
+3. Change to the directory containing Homebrew casks:
 
  ```sh
  cd "$(brew --repository homebrew/cask)"
  ```
 
-3. Add your pushable forked repository as a new remote:
+4. Add your pushable forked repository as a new remote:
 
  ```sh
  git remote add <YOUR_USERNAME> https://github.com/<YOUR_USERNAME>/homebrew-cask.git