Update readme (#5)

Signed-off-by: Reinhard Nägele <unguiculus@gmail.com>

README.md

@@ -4,6 +4,56 @@
 
 A Kubernetes operator for [Mozilla SOPS](https://github.com/mozilla/sops).
 
-----
+## Overview
 
-work in progress...
+Put SOPS-encrypted data into a `SopsSecret` which can then be committed to a Git repository.
+Once deployed on a Kubernetes cluster, the SOPS Operator will decrypt the data and create a standard Kubernetes `Secret` from it.
+
+*Example for a SopsSecret:*
+
+```yaml
+apiVersion: craftypath.github.io/v1alpha1
+kind: SopsSecret
+metadata:
+  name: test-secret
+spec:
+  stringData:
+    test.yaml: |
+      test: ENC[AES256_GCM,data:xo8jZTsQ,iv:DTouw1kgBLok6BbR5vx8366fFavV70QeCWGNQPhNb9s=,tag:RAjeoNhvGUezdOS4YOorfA==,type:str]
+      sops:
+          kms: []
+          gcp_kms: []
+          azure_kv:
+          -   vault_url: https://myakskeyvault12345567.vault.azure.net
+              name: sops
+              version: 08faa451b1d04b8bacec0395fc8539f1
+              created_at: '2020-05-01T19:42:49Z'
+              enc: DvZNm3tfyoyWibQcVPts9ODRPs3aaHbRaXOPIx1Ukypa2nPmU4RCTchBPUoqscIxDjKpSy9k6A_dfE8XAu8-XrEyuOGCEy-i6Q1OtZSGW1XnWfWXPic5TF7XCVz_08h1My1RzVUr51PPNX9uazCqQeUTfBx05KC1bT3entgfttHp-98uZkZNaI8IUUnPGCH8bZzthsXRSvRQpbZcNoOW3y04pLAVYN3xVSOdDWQSElmntg_t7eVdCsmj4iXrC-J80VPU6BoZetcsQhOLjAhXHEYMOP7fqjd2bXob59Ad8rblUDwwtcZrku5lF_LVvAKGBURxockQXmEuVAjqha1SyA
+          lastmodified: '2020-05-01T19:42:50Z'
+          mac: ENC[AES256_GCM,data:L4YfHJ59L+/YFMTizeSmEz3QiFbNYoRBVeAJNbHOCUU0W7Iv/WfGnZuNnG5c3gOELYafc812CxCFHYwoLK0bLxOd+KHwGp5IBZ7zqrg91e04V/7Tc3iEYCE3YuTQZ56XMeSSKsct7HT7jxzmVMjW0ozJ06vzQCEC/Ljsl2NfFNs=,iv:RiBXtk6Gpc/MZvDRaGKlvA8A0K7E7bGdhs8tVa6LL5w=,tag:hwnh954tiRC/VBp6LQ6nPg==,type:str]
+          pgp: []
+          unencrypted_suffix: _unencrypted
+          version: 3.5.0
+```
+
+*Here's the Secret that's created from it:*
+
+```yaml
+apiVersion: v1
+kind: Secret
+metadata:
+  name: test-secret
+data:
+  test.yaml: dGVzdDogdGVzdHZhbHVlCg==
+```
+
+## Installation
+
+A Helm chart is available in our charts repo at https://github.com/craftypath/helm-charts.
+
+```console
+helm repo add craftypath https://craftypath.github.io/helm-charts
+helm install craftypath/sops-operator
+```
+
+Check out the chart's documentation for configuration options.