Local install docs

[tasnim0tantawi]

I have tried my best to run the project locally. Everything works fine except that I'm having difficult time with .env variables.
@daveearley I need your assistance.
For client-side rendering, it works fine after a slight modification in config.ts.
For server-side rendering. It works fine after setting the environment manually in terminal.

Solving #21 and #25.

Checklist

• I have read the contributing guidelines.
• My code is of good quality and follows the coding standards of the project.
• I have tested my changes, and they work as expected.

[daveearley]

Thanks for this @tasnim0tantawi! I'll set aside some time this week to test and review it.

[daveearley]

Thanks again for this effort @tasnim0tantawi! I pushed up a few changes regarding to address the CORS issue and allow file uploads.

Cheers!