0435 python solution, tags, time/space

[ColeB2]

Change Summary

0435 - Non-overlapping Intervals

• added tags, tabs, time/space and python solution

Checklist

If you haven't fulfilled the below requirements or even delete the entire checklist, your PR won't be reviewed and will be closed without notice.

General

• [x] This Pull Request is all my own work. (You'll be blacklisted if you are caught for plagiarism.)
• [x] I've read CONTRIBUTING.md
• [x] I've applied LaTex for all variables, formulas and time / space complexity instead of using backticks
• [x] I've started the app locally and verified all the content and all links (if applicable) are accessible correctly
• [x] I've included Complexity Analysis (Time Complexity & Space Complexity).
• [x] I've written my explanation well and it is easy to understand for beginners

Solutions

• [x] I've read and followed the Solution Template
• [x] I've formatted my code well with K&R Coding style
• [x] I've confirmed that comments are put above each line rather than writing on the same line.
• [x] I've included a meaningful approach name for my solution. e.g. ## Approach 1: Two Pointers.