adding best practices to contributing

Author: mitchellirvin

README.md

@@ -6,10 +6,20 @@ I will periodically update the neetcode.io site with new solutions for this repo
 
 ### Contributing
 
-Solutions needed:
+To contribute, please fork this repo and open a PR against `main` for a problem that does not yet have a solution in a given language.
+
+Solutions needed (will be linked from [NeetCode.io](https://neetcode.io)):
 * Java
 * Javascript
 
+Solutions are also welcome for any other supported language on leetcode.com!
+
+In order to get your PR reviewed as quickly as possible, please:
+- adhere to existing naming conventions for files/directories
+- prefer adding only one solution per PR (not a hard and fast rule, but will typically make the review cycle shorter)
+- ensure your code is consistently formatted according to the language you're writing in (there are free online formatters: [formatter.org](https://formatter.org/) and [textmagic](https://freetools.textmagic.com/source-code-formatter) to name a few)
+- ensure your code passes submission on [leetcode.com](https://leetcode.com)
+
 Complete:
 * Python
 * C++