doc: Document Appveyor and Jenkins in doc/HACKING/HelpfulTools.md

Closes 26852.

doc/HACKING/HelpfulTools.md

@@ -4,9 +4,16 @@ Useful tools
 These aren't strictly necessary for hacking on Tor, but they can help track
 down bugs.
 
-Travis CI
----------
-It's CI. Looks like this: https://travis-ci.org/torproject/tor.
+Travis/Appveyor CI
+------------------
+It's CI.
+
+Looks like this:
+* https://travis-ci.org/torproject/tor
+* https://ci.appveyor.com/project/torproject/tor
+
+Travis builds and runs tests on Linux, and eventually macOS (#24629).
+Appveyor builds and runs tests on Windows (using Windows Services for Linux).
 
 Runs automatically on Pull Requests sent to torproject/tor. You can set it up
 for your fork to build commits outside of PRs too:
@@ -16,6 +23,8 @@ for your fork to build commits outside of PRs too:
    https://help.github.com/articles/fork-a-repo/
 3. follow https://docs.travis-ci.com/user/getting-started/#To-get-started-with-Travis-CI.
    skip steps involving `.travis.yml` (we already have one).
+4. go to https://ci.appveyor.com/login , log in with github, and select
+   "NEW PROJECT"
 
 Builds should show up on the web at travis-ci.com and on IRC at #tor-ci on
 OFTC. If they don't, ask #tor-dev (also on OFTC).
@@ -23,7 +32,16 @@ OFTC. If they don't, ask #tor-dev (also on OFTC).
 Jenkins
 -------
 
-    https://jenkins.torproject.org
+It's CI/builders. Looks like this: https://jenkins.torproject.org
+
+Runs automatically on commits merged to git.torproject.org. We CI the
+master branch and all supported tor versions. We also build nightly debian
+packages from master.
+
+Builds Linux and Windows cross-compilation. Runs Linux tests.
+
+Builds should show up on the web at jenkins.torproject.org and on IRC at
+#tor-bots on OFTC. If they don't, ask #tor-dev (also on OFTC).
 
 Valgrind
 --------