Add more languages

[roerohan]

Add more languages

code-executor currently supports most of the languages in src/langs. More languages need to be added so that code-executor can fulfill all requirements for popular use-cases such as Competitive Coding websites.

Structure

To add languages, you can add a Dockerfile and a start.sh script like in Python.

Note: Make sure to test the Dockerfile and the start.sh script with some sample code before making a PR to the dev branch.

[roerohan]

Added some languages in #32