docs(readme): update readme with usage instructions

Author: pascaliske

README.md

@@ -1,5 +1,30 @@
 # `helm`-charts
 
+## Usage
+
+[Helm](https://helm.sh) must be installed to use the charts. Please refer to Helm's [documentation](https://helm.sh/docs) to get started.
+
+Once Helm has been set up correctly, add the repo as follows:
+
+```sh
+helm repo add pascaliske https://charts.pascaliske.dev
+```
+
+If you had already added this repo earlier, run `helm repo update` to retrieve the latest versions of the packages.
+You can then run `helm search repo pascaliske` to see the charts.
+
+To install a chart:
+
+```sh
+helm install <chart> pascaliske/<chart>
+```
+
+To uninstall the chart:
+
+```sh
+helm delete <chart>
+```
+
 ## License
 
 [MIT](LICENSE.md) – © 2021 [Pascal Iske](https://pascaliske.dev)