CONTRIBUTING.md: Don’t open issues asking to be assigned (#788)

* CONTRIBUTING.md: Don’t open issues asking to be assigned

This habit makes us slow and chatty so let’s discourage it.

* Update CONTRIBUTION.md

There are many issues asking permission for a pull request, instead a direct pull request for evaluation is of much help.

* Update CONTRIBUTION.md
Co-authored-by: NSombit Bose <sombit.bose15@gmail.com>

CONTRIBUTION.md

@@ -13,6 +13,7 @@ We are very happy that you consider implementing algorithms and data structures
 
 **New implementation** New implementation are welcome!
 **Improving comments** and **adding tests** to existing algorithms are much appreciated.
+**Issues** Please avoid opening issues asking to be "assigned” to a particular algorithm.  This merely creates unnecessary noise for maintainers.  Instead, please submit your implementation in a pull request and it will be evaluated by project maintainers.
 
 ### Making Changes