doc: Update contributing guidelines

References:

  * Issue not in English: https://github.com/yagop/node-telegram-bot-api/issues/460

CONTRIBUTING.md

@@ -10,6 +10,15 @@ Before proceeding any further, read the following documents:
 
 ## General Information
 
+### Creating a Github issue:
+
+1. Ensure that your issue does **not** already exist. [Do a search](https://github.com/yagop/node-telegram-bot-api/issues).
+2. Browse through [StackOverflow](https://stackoverflow.com/search?q=telegram+nodejs) and other similar platforms.
+3. Should you open your issue, ensure you use the English language for
+   the wider target audience.
+4. Be patient please.
+
+
 ### Updating API Reference i.e. generating `doc/api.md`
 
 Run: