Update README.md to not reflect cache keys since it is now abstracted.

README.md

@@ -17,7 +17,6 @@ Create a workflow `.yml` file in your repositories `.github/workflows` directory
 
 ### Inputs
 
-* `key` - Unique key representing the cache being used.
 * `packages` - Space delimited list of packages to install.
 
 ### Outputs
@@ -26,9 +25,7 @@ Create a workflow `.yml` file in your repositories `.github/workflows` directory
 
 ### Cache scopes
 
-The cache is scoped to the key and branch. The default branch cache is available to other branches.
-
-See [Matching a cache key](https://help.github.com/en/actions/configuring-and-managing-workflows/caching-dependencies-to-speed-up-workflows#matching-a-cache-key) for more info.
+The cache is scoped to the packages given and the branch. The default branch cache is available to other branches.
 
 ### Example workflow
 
@@ -48,7 +45,6 @@ jobs:
       - uses: actions/checkout@v2
       - uses: awalsh128/cache-apt-pkgs-action-action@v1
         with:
-          cache_key: doxygen_env
           packages: dia doxygen doxygen-doc doxygen-gui doxygen-latex graphviz mscgen
 
       - name: Build        
@@ -63,37 +59,6 @@ jobs:
           folder: ${{github.workspace}}/build/website
 ```
 
-## Creating a cache key
-
-A cache key can include any of the contexts, functions, literals, and operators supported by GitHub Actions.
-
-For example, using the [`hashFiles`](https://help.github.com/en/actions/reference/context-and-expression-syntax-for-github-actions#hashfiles) function allows you to create a new cache when dependencies change.
-
-```yaml
-  - uses: awalsh128/cache-apt-pkgs-action@v1
-    with:
-      cache_key: ${{ runner.os }}-${{ hashFiles('**/lockfiles') }}
-      packages: dot
-```
-
-Additionally, you can use arbitrary command output in a cache key, such as a date or software version:
-
-```yaml
-  # http://man7.org/linux/man-pages/man1/date.1.html
-  - name: Get Epoch Seconds
-    id: get-epoch-sec
-    run: |
-      echo "::set-output name=epoch_sec::$(/bin/date +%s)"
-    shell: bash
-
-  - uses: awalsh128/cache-apt-pkgs-action@v1
-    with:
-      cache_key: ${{ runner.os }}-${{ steps.get-epoch-sec.outputs.epoch_sec }}-${{ hashFiles('**/lockfiles') }}
-      packages: dot
-```
-
-See [Using contexts to create cache keys](https://help.github.com/en/actions/configuring-and-managing-workflows/caching-dependencies-to-speed-up-workflows#using-contexts-to-create-cache-keys)
-
 ## Cache Limits
 
 A repository can have up to 5GB of caches. Once the 5GB limit is reached, older caches will be evicted based on when the cache was last accessed.  Caches that are not accessed within the last week will also be evicted.