Update documentation

Author: kyle-leonhard

README.md

@@ -25,7 +25,7 @@ See [action.yml](action.yml)
     # Examples: 12.x, 10.15.1, >=10.15.0, lts/Hydrogen, 16-nightly, latest, node
     node-version: ''
 
-    # File containing the version Spec of the version to use.  Examples: package.json, .nvmrc, .node-version, .tool-versions.
+    # File containing the version Spec of the version to use.  Examples: package.json, .nvmrc, .node-version, .tool-versions, .npmrc.
     # If node-version and node-version-file are both provided the action will use version from node-version. 
     node-version-file: ''
 

__tests__/README.md

@@ -2,7 +2,7 @@ Files located in data directory are used only for testing purposes.
 
 
 ## Here the list of files in the data directory
- - `.nvmrc`, `.tools-versions` and `package.json` are used to test node-version-file logic
+ - `.nvmrc`, `.tools-versions`, `package.json` and `.npmrc` are used to test node-version-file logic
  - `package-lock.json`, `pnpm-lock.yaml` and `yarn.lock` are used to test cache logic 
  - `versions-manifest.json` is used for unit testing to check downloading Node.js versions from the node-versions repository.
  - `node-dist-index.json` is used for unit testing to check downloading Node.js versions from the official site. The file was constructed from https://nodejs.org/dist/index.json

action.yml

@@ -8,7 +8,7 @@ inputs:
   node-version:
     description: 'Version Spec of the version to use. Examples: 12.x, 10.15.1, >=10.15.0.'
   node-version-file:
-    description: 'File containing the version Spec of the version to use.  Examples: package.json, .nvmrc, .node-version, .tool-versions.'
+    description: 'File containing the version Spec of the version to use.  Examples: package.json, .nvmrc, .node-version, .tool-versions, .npmrc.'
   architecture:
     description: 'Target architecture for Node to use. Examples: x86, x64. Will use system architecture by default.'
   check-latest:

docs/advanced-usage.md

@@ -56,7 +56,7 @@ steps:
 
 ## Node version file
 
-The `node-version-file` input accepts a path to a file containing the version of Node.js to be used by a project, for example `.nvmrc`, `.node-version`, `.tool-versions`, or `package.json`. If both the `node-version` and the `node-version-file` inputs are provided then the `node-version` input is used.
+The `node-version-file` input accepts a path to a file containing the version of Node.js to be used by a project, for example `.nvmrc`, `.node-version`, `.tool-versions`, `package.json`, or `.npmrc`. If both the `node-version` and the `node-version-file` inputs are provided then the `node-version` input is used.
 See [supported version syntax](https://github.com/actions/setup-node#supported-version-syntax).
 
 > The action will search for the node version file relative to the repository root.