feat: add change language in sidebar and update translation json files

[ansh-saini]

Description

Add a dropdrown for change language in sidebar as requested in #1005

Motivation

Hacktoberfest 2020

Testing Guidelines

Release Checklist

• This code has unit tests
• I have a plan to verify that these changes are working as expected after deploy
• I have a plan for how to revert, rollback, or disable these changes if things are not working as expected

Security Checklist

This PR creates, modifies, or deletes:

• API routes: API routes, parameters, or user authorization
• Authentication: Authentication mechanism
• Credentials: Server side credentials, or secrets in configuration / source code
• Cryptography: Encryption, hashing, certificates, signatures, random numbers, etc.
• User data: personal information handling, logs, error messages, etc.

Additional Notes

[shayantist]

@ethanstrominger why was this closed before merging?

[ashwinkjoseph]

@ethanstrominger there were a few more improvements I would have liked @ansh-saini to make here but overall it looked all right.
I don't think we should close PRs without appropriate reason and explaining it. We should also try to request changes and get a PR fixed rather than closing it. We should resort to closing only if the PR is not relevant to us.
I am re-opening this PR, please mention the reason why this has to be closed

[ashwinkjoseph]

LGTM!,
@ansh-saini you only had to change the language in English translation file, we had a tool that would automatically fill it in for the other languages.
I guess this is what you were asking for in slack, sorry misunderstood you then.

[ashwinkjoseph]

@ethanstrominger I am not merging it now, have a look at it and let me know if it can be merged or not.

[ethanstrominger]

@ashwinkjoseph I closed it by mistake.

[ashwinkjoseph]

alright, I've merged it

[ansh-saini]

Thank you 😄

[ansh-saini]

@ethanstrominger Can you please add the hacktoberfest-accepted label to this PR?

[ethanstrominger]

@ansh-saini I applied the hacktoberfest-accepted label.

[shayantist]

Thanks for the help Ansh! @all-contributors please add @ansh-saini for code

[allcontributors]

@schowdhury8

I've put up a pull request to add @ansh-saini! 🎉