Improve documentation around pathspec error behavior (#706)

* Clarify pathspec error behavior can be configured

Fixes #705

* Fix typo "this" -> "these"

Author: tomas-kovanda

CONTRIBUTING.md

@@ -1,6 +1,6 @@
 # Contributing
 
-If you want to contribute to this project, check out this steps!
+If you want to contribute to this project, check out these steps!
 
 1. Check out existing features to make sure your case is not already covered. Also, try [searching open or closed issues](https://github.com/EndBug/add-and-commit/issues) that may cover the same topic.
 2. Either [open a new issue](https://github.com/EndBug/add-and-commit/issues/new/choose) or comment on an existing one to let everyone know what you're working on.

README.md

@@ -104,7 +104,7 @@ What does this mean for you? It means that strings that contain a lot of nested
 ### Adding files
 
 The action adds files using a regular `git add` command, so you can put every kind of argument in the `add` option. For example, if you want to force-add a file: `./path/to/file.txt --force`.  
-The script will not stop if one of the git commands doesn't match any file. E.g.: if your command shows a "fatal: pathspec 'yourFile' did not match any files" error the action will go on.  
+The script will not stop if one of the git commands doesn't match any file. E.g.: if your command shows a "fatal: pathspec 'yourFile' did not match any files" error the action will go on, unless specified otherwise with `pathspec_error_handling`.  
 You can also use JSON or YAML arrays (e.g. `'["first", "second"]'`, `"['first', 'second']"`) to make the action run multiple `git add` commands: the action will log how your input has been parsed. Please mind that your input still needs to be a string because of how GitHub Actions works with inputs: just write your array inside the string, the action will parse it later.
 
 ### Deleting files