Added installing-numpy.md file and updated the index.md

[Yodha-Sudarsi]

PR Description

Added installing-numpy.md file and updated the index.md

Related Issues

#78

• Closes installing numpy #78

Checklist

• [x] I have gone through the contributing guide
• [x] I have updated my branch and synced it with project main branch before making this PR

Undertaking

I declare that:

1. The content I am submitting is original and has not been plagiarized.
2. No portion of the work has been copied from any other source without proper attribution.
3. The work has been checked for plagiarism, and I assure its authenticity.

I understand that any violation of this undertaking may have legal consequences that I will bear and could result in the withdrawal of any recognition associated with the work.

• [x] I Agree

[Yodha-Sudarsi]

I'm really sorry @animator , Could you please keep the request open? This won't happen again. I realized I needed to change the PR description because we were having a conversation there. I changed the file accordingly after refering to #119

[Yodha-Sudarsi]

Hi @animator, completed #78. I also completed the latest task #160. But the issue is I can only send pull request if you merge or close #78 after reviewing. Thank you and have a nice day man...

[animator]

File names should be - separated not _ separated. You can create separate PRs. You just need to have a separate branch for each issue fix. Also, for array operation, it should be - explain what the operator does followed by code example for the operator. Go though the learn python book to understand it better. Closing this PR. Raise two separate PRs fixing all the issues.