updated headers

Author: AlenaSviridenko

README.md

@@ -32,7 +32,7 @@ The action will first check the local cache for a semver match. If unable to fin
 
 For information regarding locally cached versions of Node.js on GitHub hosted runners, check out [GitHub Actions Virtual Environments](https://github.com/actions/virtual-environments).
 
-**Caching npm dependencies:**
+### Caching packages dependencies
 
 The action has a built-in functionality for caching and restoring npm/yarn dependencies. Supported package managers are `npm`, `yarn`. The `cache` input is optional, and caching is turned off by default.
 
@@ -62,7 +62,7 @@ Yarn caching handles both yarn versions: 1 or 2.
 
 > At the moment, only `lock` files in the project root are supported.
 
-**Matrix Testing:**
+### Matrix Testing:
 ```yaml
 jobs:
   build: