Merge pull request #744 from corneliusroemer/patch-2

Explain what's done and that there can be false negatives

README.md

@@ -2,11 +2,13 @@
   <a href="https://github.com/marocchino/validate-dependabot/actions"><img alt="typescript-action status" src="https://github.com/marocchino/validate-dependabot/workflows/build-test/badge.svg"></a>
 </p>
 
+This action tests the dependabot.yml against the official JSON schema. It does not detect all invalid dependabot files as dependabot has extra validation beyond the JSON schema.
+
 ## Why?
 
 If you get a validation error when editing your config, you won't know if there's a problem until the next dependabot runs.
 Even if the cycle is long and the alarm is not set, it may be detected much later.
-This library allows you to find problems in the PR stage.
+This library allows you to find some problems in the PR stage.
 
 ## Usage