Add branch pointing to config instead of package scripts (#5616)

# Pull Request

## 📖 Description

<!---
Provide some background and a description of your work.
What problem does this change solve?
Is this a breaking change, chore, fix, feature, etc?
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This change moves the branch specificity to beachball config to allow `yarn change` to target the feature branch and also removes the restriction on "major" change updates.

## ✅ Checklist

### General

<!--- Review the list and put an x in the boxes that apply. -->

- [ ] I have included a change request file using `$ yarn change`
- [ ] I have added tests for my changes.
- [x] I have tested my changes.
- [ ] I have updated the project documentation to reflect my changes.
- [x] I have read the [CONTRIBUTING](https://github.com/Microsoft/fast/blob/master/CONTRIBUTING.md) documentation and followed the [standards](https://www.fast.design/docs/community/code-of-conduct/#our-standards) for this project.

beachball.config.js

@@ -1,5 +1,5 @@
 module.exports = {
-    disallowedChangeTypes: ["major"],
+    branch: "origin/features/fast-element-2",
     ignorePatterns: [
         ".ignore",
         ".github/",

package.json

@@ -42,7 +42,7 @@
   "scripts": {
     "bump": "beachball bump",
     "change": "beachball change",
-    "checkchange": "beachball check  --scope \"!sites/*\" --changehint \"Run 'yarn change' to generate a change file\" -b origin/features/fast-element-2",
+    "checkchange": "beachball check  --scope \"!sites/*\" --changehint \"Run 'yarn change' to generate a change file\"",
     "check": "beachball check ",
     "publish": "beachball publish",
     "publish-ci": "beachball publish -y --access public",