Support prek.toml and .pre-commit-config.yml in cache key (#65)

Expand hashFiles() to cover all three config filenames that prek
recognizes (prek.toml, .pre-commit-config.yaml, .pre-commit-config.yml).
Update README requirements to reflect the supported config files.

Closes #64

---------

Co-authored-by: Jo <10510431+j178@users.noreply.github.com>

Author: shaanmajid

README.md

@@ -95,7 +95,7 @@ Running `prek` in a separate step can be useful for example when you need to cus
 
 ## Requirements
 
-Your repository must have a `.pre-commit-config.yaml` file configured for use with pre-commit hooks.
+Your repository must have a [prek configuration](https://prek.j178.dev/configuration/) file (`prek.toml`, `.pre-commit-config.yaml`, or `.pre-commit-config.yml`).
 
 ## License
 

action.yaml

@@ -118,7 +118,7 @@ runs:
       # `env.pythonLocation` is set by `actions/setup-python`, pointing to the directory where Python is installed.
       # prek doesn't require Python, but the hooks it runs often do (e.g., pre-commit hooks), changing the Python version makes Python virtual environments invalid.
       # So we include it in the cache key to avoid using invalid caches.
-      key: prek-v1|${{ runner.os }}|${{ runner.arch }}|${{ env.pythonLocation }}|${{ hashFiles(format('{0}/**/.pre-commit-config.yaml', inputs.working-directory)) }}
+      key: prek-v1|${{ runner.os }}|${{ runner.arch }}|${{ env.pythonLocation }}|${{ hashFiles(format('{0}/**/prek.toml', inputs.working-directory), format('{0}/**/.pre-commit-config.yaml', inputs.working-directory), format('{0}/**/.pre-commit-config.yml', inputs.working-directory)) }}
 
   - name: Run prek
     if: inputs.install-only == 'false'