add contributing guide

CONTRIBUTING.md

@@ -0,0 +1,100 @@
+# Contributing Guide
+
+Thank you for your interest in contributing to the Application Study Tool!
+Please read this guide for general guidelines to follow, which borrows heavily
+from those used by the Opentelemetry Collector.
+
+## How to contribute
+
+### Before you start
+
+Comment on the issue that you want to work on so we can assign it to you and
+clarify anything related to it.
+
+If you would like to work on something that is not listed as an issue,
+please create an issue and describe your proposal. It is best to do this
+in advance so that maintainers can decide if the proposal is a good fit for
+this repository. This will help avoid situations when you spend significant time
+on something that maintainers may decide this repo is not the right place for.
+
+Follow the instructions below to create your PR.
+
+### Fork
+
+In the interest of keeping this repository clean and manageable, you should
+work from a fork. To create a fork, click the 'Fork' button at the top of the
+repository, then clone the fork locally using `git clone
+[email protected]:USERNAME/ast-api-discovery.git`.
+
+You should also add this repository as an "upstream" repo to your local copy,
+in order to keep it up to date. You can add this as a remote like so:
+
+`git remote add upstream https://github.com/f5devcentral/ast-api-discovery.git`
+
+Verify that the upstream exists:
+
+`git remote -v`
+
+To update your fork, fetch the upstream repo's branches and commits, then merge
+your `development` with upstream's `development`:
+
+```
+git fetch upstream
+git checkout development
+git merge upstream/development
+```
+
+Remember to always work in a branch of your local copy, as you might otherwise
+have to contend with conflicts in `development`.
+
+
+## Required Tools
+
+Working with the project sources requires the following tools:
+
+1. [git](https://git-scm.com/)
+4. [docker](https://www.docker.com/)
+
+## Repository Setup
+
+Fork the repo and checkout  by:
+
+```
+$ git clone [email protected]:f5devcentral/ast-api-discovery.git
+```
+
+Add your fork as an origin:
+
+```shell
+$ cd ast-api-discovery
+$ git remote add fork [email protected]:YOUR_GITHUB_USERNAME/ast-api-discovery.git
+```
+
+## Creating a PR
+
+Checkout a new branch, make modifications, build locally, and push the branch to your fork
+to open a new PR:
+
+```shell
+$ git checkout development
+$ git checkout -b feature
+# edit
+$ git commit
+$ git push fork feature
+```
+
+### Commit Messages
+
+Use descriptive commit messages. Here are [some recommendations](https://cbea.ms/git-commit/)
+on how to write good commit messages.
+When creating PRs GitHub will automatically copy commit messages into the PR description,
+so it is a useful habit to write good commit messages before the PR is created.
+Also, unless you actually want to tell a story with multiple commits make sure to squash
+into a single commit before creating the PR.
+
+When maintainers merge PRs with multiple commits, they will be squashed and GitHub will
+concatenate all commit messages right before you hit the "Confirm squash and merge"
+button. Maintainers must make sure to edit this concatenated message to make it right before merging.
+In some cases, if the commit messages are lacking the easiest approach to have at
+least something useful is copy/pasting the PR description into the commit message box
+before merging (but see the above paragraph about writing good commit messages in the first place).