make main as default branch (#1288)

## High Level Overview of Change

Make `main` as default branch to avoid `staging` to `main` PR during
release. This also helps removing all the users who have push to main
access and all the commits go through pull request reviews before they
are merged and released.

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### Context of Change

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### Type of Change

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- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] Refactor (non-breaking change that only restructures code)
- [ ] Tests (You added tests for code that already exists, or your new
feature included in this PR)
- [ ] Documentation Updates
- [ ] Translation Updates
- [ ] Release

### Codebase Modernization

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- [ ] Updated files to TypeScript

## Before / After

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## Test Plan

1. Existing tests should pass.
2. CI should run and pass.
3. Force push on main should not be allowed. - Works - remote: - Changes
must be made through a pull request. error: failed to push some refs to
'github.com:ripple/explorer.git'
4. Requires 2 approvals before merge into main.

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Author: Patel-Raj11

.github/workflows/nodejs.yml

@@ -2,7 +2,7 @@ name: Explorer CI
 
 on:
   push:
-    branches: [main, staging]
+    branches: [main]
   pull_request:
   workflow_dispatch:
 

CONTRIBUTING.md

@@ -30,25 +30,25 @@ You need only to do this once and you have probably already done this if you alr
 ### Clone the repository on your local machine.
 
 ```
-$ git clone [email protected]:username/explorer.git --branch staging
+$ git clone [email protected]:username/explorer.git --branch main
 $ cd explorer
 $ git remote add upstream [email protected]:ripple/explorer.git
 ```
 
 ### Start work in a new branch.
 
 ```
-$ git fetch upstream staging
-$ git checkout staging
+$ git fetch upstream main
+$ git checkout main
 $ git checkout -b your-branch-name
 $ git push --set-upstream origin your-branch-name
 ```
 
-Bring in recent changes to the “staging” branch into your own branch
+Bring in recent changes to the “main” branch into your own branch
 
 ```
-$ git fetch upstream staging
-$ git pull upstream staging
+$ git fetch upstream main
+$ git pull upstream main
 ```
 
 ### Ask to submit code from a branch of your GitHub fork.

README.md

@@ -1,6 +1,6 @@
 [![Release](https://img.shields.io/github/v/release/ripple/explorer.svg)](https://github.com/ripple/explorer/releases)
 [![Build](https://github.com/ripple/explorer/actions/workflows/nodejs.yml/badge.svg)](https://github.com/ripple/explorer/actions)
-[![License](https://img.shields.io/github/license/ripple/explorer)](https://github.com/ripple/explorer/blob/staging/LICENSE)
+[![License](https://img.shields.io/github/license/ripple/explorer)](https://github.com/ripple/explorer/blob/main/LICENSE)
 
 # XRPL Explorer