add github repo to local project code example

Example: how to send your code to github

We make a change in one branch, and we want carry that
change to another branch. In order two merge two branches,
we need to
1. Switch to the branch where we want to take the changes to.
git checkout master(recently changed to main)
2. Run the merge command by mentioning the branch name
where the changes are.
git merge develop
Takes the changes from develop and merges into my current
branch (master)
git branch -d <branch_name> deletes the branch.
If we have unmerged changes, this command gives a warning
and does not delete.
git branch -D <branch_name> deletes the branch even if it has
unmerged changes. Gives no warning.
git push --set-upstream origin <branch_name> it creates a
new branch with given name in the remote and pushes the
changes from local branch to the new branch.