Adding documentation for all features

Author: Nyholm

README.md

@@ -25,3 +25,84 @@ are up to date.
 
 Carson will never read the contents of a pull requests, ie it never parses the code
 to check for typos or other automated fixes.
+
+## Features
+
+Here is all the things Carson can help you with. Not all features are enabled. A
+list of enabled features for a specific repository is defined in `config/services.yaml`.
+
+### Automatic labeling from content
+
+Using the issue template, Carson adds labels "Bug", "Feature", "BC Break"
+and "Deprecation" on issues and pull requests.
+
+### Add "Needs Review" label on pull requests
+
+When a PR is opened, then Carson will add "Needs Review".
+
+### Add "Needs Review" label on bugs issues
+
+If an issue is labeled with "Bug", then Carson will add "Needs Review".
+
+### Update pull request title with component labels
+
+When a PR is labeled, Carson looks for component labels (i.e. labels with color #dddddd).
+These labels' names will be added to the PR title (e.g. `[HttpKernel]`).
+
+### Close draft pull requests
+
+When a PR is open as "draft", Carson adds a comment to encourage people to mark it as
+"ready to review". If no action is taken, Carson will close the PR in one hour.
+
+### Add milestone to PRs
+
+When a new PR is opened and it does not target the default branch or current version, then
+Carson will update the milestone of the PR to a existing milestone that matches the target branch.
+
+### Manage pull request status
+
+The "status" of a pull request defined by one of the labels: "Needs review", "Needs work",
+"Works for me" and "Reviewed". The status can be changed by adding a comment like:
+"Status: needs work".
+
+The status will also be changed if someone adds a review that requests changes or
+approves the PR. Finally, the status will be "Needs review" after the author pushes
+changes to the PR.
+
+### Welcome new contributors
+
+When a user opens their first PR, they will get a welcome message explaining the
+review process and how to increase the chances to get the PR merged.
+
+### Comment on stale issues
+
+Carson will look for old inactive issues and start a process with them.
+
+1. Bot will make a comment to encourage activity and add label "Staled".
+1. Bot will make a comment to inform the issue will be closed
+1. Bot will close the issue.
+
+The process can be interrupted with anyone making a comment on the issue or the
+"Keep open" label is added.
+
+### Suggest reviewers
+
+Carson can look at the PR to figure out who will be a good candidate to review the
+changes. This can be triggered by someone can make a comment in a PR to say
+`@carsonbot find me a reviewer please` (or really anything with `@carsonbot` and
+`review` on the same line).
+
+Carson will also try to find a reviewer if there is no activity on a new PR within
+the first 20 hours.
+
+### Add a warning if pull request target unsupported branch
+
+If a PR is opened towards a branch that is not maintained anymore, Carson will
+kindly explain to the author what to do.
+
+### Open issues when docs for config reference is incomplete
+
+The Symfony documentation includes some pages with "configuration reference", to
+make sure these are always up to date, Carson will look at the bundles' defined
+config and compare that to what is documented. If Carson finds something that is
+missing, it will open an issue in the symfony/symfony-docs repository.