Fresh pull request for sorting algorithms

[Ahel2000]

Description

Add insertion sort, selection sort and merge sort.

Issue #5

Type of change

Please delete options that are not relevant.

• [x] Added Algorithm
• [x] Folder Structure

Added to SUMMARY.md (delete section if not needed)?

Have you added the page to SUMMARY.md if this is a new page and not a fix?

• [x] Yes
• [ ] No

[sadn1ck]

@Ahel2000 do we need the .java files? You already added code in the markdown files. @arnabsen1729 opinion?

[Ahel2000]

I have made the changes @arnabsen1729

[sadn1ck]

@allcontributors add @Ahel2000 for contributing to documentation

[allcontributors[bot]]

@sadn1ck

I've put up a pull request to add @Ahel2000! :tada: