chore: add usage instructions to readme file

ui/StatusQ/README.md

@@ -1,3 +1,50 @@
 # Status QML
 
 > An emerging reusable UI component library for Status applications.
+
+## Usage
+
+StatusQ introduces a module namespace that semantically groups components so they can be easily imported.
+These modules are:
+
+- [StatusQ.Core](https://github.com/status-im/StatusQ/blob/master/src/StatusQ/Core/qmldir)
+- [StatusQ.Core.Theme](https://github.com/status-im/StatusQ/blob/master/src/StatusQ/Core/Theme/qmldir)
+
+Provided components can be viewed and tested in the [sandbox application](#viewing-and-testing-components) that comes with this repository.
+Other than that, modules and components can be used as expected.
+
+Example:
+
+```
+import Status.Core 0.1
+import Status.Controls 0.1
+
+StatusInput {
+  ...
+}
+```
+
+## Viewing and testing components
+
+To make viewing and testing components easy, we've added a sandbox application to this repository in which StatusQ components are being build. This is the first place where components see the light of the world and can be run in a proper application environment.
+
+### Using Qt Creator
+
+The easiest way to run the sandbox application is to simply open the provided `sandbox.pro` file using Qt Creator.
+
+### Using command line interface
+
+To run the sandbox from within a command line interface, run the following commands:
+
+```
+$ git clone https://github.com/status-im/StatusQ
+$ cd StatusQ/sandbox
+$ qmake sandbox.pro -spec macx-clang CONFIG+=debug CONFIG+=x86_64 && /usr/bin/make qmake_all
+$ make
+```
+
+Once that is done, the sandbox can be started with the generated executable:
+
+```
+$ ./bin
+```