Fix Markdown according to markdown-lint

.github/CONTRIBUTING.md

@@ -3,6 +3,7 @@
 This is a compilation of **Free and Libre Open Source Software ([FLOSS](https://en.wikipedia.org/wiki/Free_and_open-source_software))**. Restrictive licenses (aka Freeware, Shareware) are *not awesome*. Please adhere to the following guidelines or your Pull Request will be closed.
 
 ## Commits
+
 * Search previous suggestions before making a new one.
 * Use the following format: `[RESOURCE](LINK) - DESCRIPTION.`
   * Keep descriptions short (<80 characters).
@@ -11,6 +12,7 @@ This is a compilation of **Free and Libre Open Source Software ([FLOSS](https://
   * Order projects alphabetically.
 
 ## Pull Requests
+
 * Consolidate multiple commits.
 * Use imperative (e.g. add instead of added/adding) in the PR title.
 * Include application names, categories and a link to the open source project page in the description.
@@ -18,6 +20,7 @@ This is a compilation of **Free and Libre Open Source Software ([FLOSS](https://
   * Put only stuff on the list you or another contributor can personally recommend
 
 ## Issues
+
 * Discussion, questions and bug reports only.
 * If you are sure software meets the guidelines, create a Pull Request (see above).
 * Check spelling and grammar.