restore composer.json, add mysqli extension

public/vendor/editor/.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,31 @@
+Thank you for taking the time to help us improve Summernote.
+Please be sure that you are not submitting changes made to the files in the `dist/` folder, and only to the files contained in the `src/` folder.
+
+#### What does this PR do?
+
+- awesome stuff
+- really cool feature
+- refactor X
+
+#### Where should the reviewer start?
+
+- start on the src/summernote.js
+
+#### How should this be manually tested?
+
+- click here and here
+
+#### Any background context you want to provide?
+
+- the gem needed to be updated...
+
+#### What are the relevant tickets?
+
+
+#### Screenshot (if for frontend)
+
+
+### Checklist
+- [ ] added relevant tests
+- [ ] didn't break anything
+- [ ] ...