Add Categories to ease navigation

[rossilor95]

How about assigning categories to the snippets? Some examples:

• Simple Numbers (Find a digit in a specific place in a number, find generic root, etc)
• Calculation
• Geometry
• Special Numbers (Fibonacci, Palindrome, Armstrong, etc.)
• Unit Conversion

[harshraj8843]

👋🏻 Hey @rossilor95

That will be awesome 👍🏻

This feature will be added soon 🚀

Contribute to this feature

• You are welcome to raise a PR for add category #891
• Add category in README.md for specific programmes

...
image: hero.png
+ category:
+   - addition
+   - simple numbers
tags:
  - python
  - cs
  - cpp
  - java
  - go
  - c
  - js
contributors:
  - harshi1122
...