Add release build instructions to README

Author: Tykky

README.md

@@ -340,6 +340,46 @@ We've used [cargo-wix](https://github.com/volks73/cargo-wix) to create the Windo
 Further instructions for it's usage can be found on the given repository.
 Please mind that the *License.rtf* has been modified (for the copyright part) and changed the manufacturer has been to University of Helsinki in the *main.wxs* file. We have not implemented creating the installer in the GitHub Actions, so it needs to be done manually.
 
+Github actions builds every commit and runs all tests on them on every supported platform. When tests
+are successful there is a option to create a release build. These are triggered by creating a
+tag on the commit you want to create release from. Usually commits are tagged with version like this:
+```
+git tag v0.0.1
+```
+Only hard requirement is that all tags which are used to create release builds **must begin with letter v**.
+Release builds are uploaded to [download.mooc.fi](https://download.mooc.fi/). Each release can be downloaded
+by using url:
+```
+https://download.mooc.fi/tmc-cli-rust/tmc-cli-rust-<ARCH>-<PLATFORM>-<VERSION>.<EXT>
+```
+
+where each <> should be replaced with one of these:
+
+ - ARCH: x86_64, i686
+ - PLATFORM: pc-windows-msvc, unknown-linux-gnu, apple-darwin
+ - VERSION: This one is given by the tag (e.g v0.0.1)
+ - EXT: On windows: exe. On other platforms this is empty.
+
+When in doubt, you can always check all downloadable files at [download.mooc.fi](https://download.mooc.fi/)
+by examining the xml file manually.
+
+For example x86_64 downloads for v.0.3.5 look like this:
+```
+https://download.mooc.fi/tmc-cli-rust/tmc-cli-rust-x86_64-unknown-linux-gnu-v0.3.5
+https://download.mooc.fi/tmc-cli-rust/tmc-cli-rust-x86_64-apple-darwin-v0.3.5
+https://download.mooc.fi/tmc-cli-rust/tmc-cli-rust-x86_64-pc-windows-msvc-v0.3.5.exe
+```
+
+When it comes to creating releases, our typical workflow looks like this:
+
+First make sure that all tests pass then:
+```
+git checkout main
+git merge dev
+git tag v0.0.1
+git push --tags
+```
+
 ### Formatting
 
 Code should be formatted with [rustfmt](https://github.com/rust-lang/rustfmt)