Update README

Closes #57

README.md

@@ -1,4 +1,39 @@
 # CentralHub
-Central hub stuff
 
-API communication between trackers and webfront
+This project contains the components of the CentralHub.
+The CentralHub takes measurements from [esp32-trackers](https://github.com/cs-23-sw-7-06/esp32-tracker) and aggregates it to derive a occupancy estimate for a given room.
+It contains two servers.
+
+
+## REST API
+
+The REST API (CentralHub.Api) is called both by the trackers and the Web UI.
+It exposes endpoints for managing rooms, trackers, and measurements.
+Every 5 minutes it takes all measurements from the trackers and aggregates them to provide occupancy estimation for all registered rooms.
+
+
+## Web UI
+
+This (CentralHub.WebUI) uses the REST API and provides a user interface for the REST API.
+More specifically, it allows the user to manage rooms and trackers, and show historical data for occupancy in a given registered room.
+
+
+## Building
+
+The project can be build in Visual Studio, any other IDE, or simply using the commands:
+
+```bash
+dotnet publish CentralHub.Api -c "Release"
+dotnet publish CentralHub.WebUI -c "Release"
+```
+
+However, running on archlinux the [CentralHub-PKGBUILD](https://github.com/cs-23-sw-7-06/CentralHub-PKGBUILD) package is recommended instead as it provides preconfigured hardened systemd services for running this system.
+
+
+### Tests
+
+Unit tests are defined in the CentralHub.Api.Tests project and can be run with the command:
+
+```bash
+dotnet test
+```