docs: command cheat sheet (microsoft#30685)

docs/react-v9/contributing/command-cheat-sheet.md

@@ -1,4 +1,31 @@
-// TODO #30642 A doc showing a table of every day commands.
+This is a helpful list of helpful every day commands.
 
-Assignee - Mason
-Reviewer - Esteban
+yarn // installs everything. It fixes many things.
+yarn buildto package-name // Does a yarn build scoped to a specific package and its dependencies for faster speeds vs building the whole repo.
+yarn test // runs a test suite. It is slightly different from the test suite in the CI/CD test suite. Can be run from inside a given package to run faster.
+yarn create-package // scaffolds a new package
+yarn create-component // scaffolds a new component
+yarn change // creates a new change file, if needed
+yarn clean // tidies any cached dependencies
+yarn start // runs a package. You can select the package of choice.
+yarn update-snapshots // updates snapshot tests
+yarn run dedupe // dedupes dependencies - necessary to run after any kind of package bump/changes
+yarn nx run <package-name>:generate-api // updates API files
+yarn nx run <package-name>:<target-name> // runs tasks within a package. [More help here][https://nx.dev/features/run-tasks#running-tasks]
+
+git checkout user/jdoe/some-fancy-branch-name // checks out an existing branch
+git checkout -b user/jdoe/some-fancy-branch-name // creates a branch initially
+git status // shows a list of changed files.
+git add . // stages all your changed files
+git add some/file/name // adds a specific file to the change set
+git commit -m "your commit message" // commits all your staged files
+git commit -a -m "some commit message" // stages and commits everything in one command.
+git pull upstream master // pulls the latest version of master to your local machine from the root repo, not your fork
+git rebase master // tacks all your commits from your current branch onto the end of master. Prefer this over merges.
+git rebase -i master // shows your list of commits about to rebased before it's committed.
+git branch // lists all the branches on your local machine
+git push // pushes things to your forked repo, not the main repo.
+git push upstream // pushes your branch to the main repo.
+git push upstream --force // force is needed after a rebase.
+
+lage build --to react // build v8 so intellisense works.