feat(docs): add building instructions

README.md

@@ -12,4 +12,33 @@ sessions and breaks.
 
 ![](docs/media/reset-after-inactivity-for.png)
 
-![](docs/media/keep-time-logs-for.png)
+![](docs/media/keep-time-logs-for.png)
+
+# Installation
+### Binary releases
+You can find binary versions of Timeow on the [Releases](https://github.com/f-person/timeow-mac/releases)
+page on GitHub.
+
+Please not that the binaries from Releases page are not signed so you will need
+to the first time you'll need to open them by right clicking in Finder:
+Finder -> Applications -> Timeow -> Right click -> Open.
+
+### Building from source
+
+In order to build a regular binary, you need to have a macOS machine with Go installed.
+The following command will generate 3 versions of Timeow – `amd64`, `arm64`, and
+a universal binary. They will be located in the `build` directory.
+```sh
+make build
+```
+
+If you want to build `Timeow.app`, you need a macOS machine with Go and Xcode.
+```sh
+make dist-mac-app
+```
+
+If you want to build a dmg, you need a macOS machine with Go, Xcode and
+[create-dmg](https://github.com/create-dmg/create-dmg/).
+```sh
+make dist-mac-dmg
+```