Add development instructions (#13)

Author: kangasta

README.md

@@ -2,6 +2,20 @@
 
 Examples on how to develop CI/CD pipelines and how to configure development environment for working with CI/CD pipelines.
 
+## Developing
+
+Install dependencies:
+
+```sh
+pip3 install -r requirements.txt
+```
+
+Start development server:
+
+```sh
+mkdocs serve
+```
+
 ## License
 
 CI/CD Examples is licensed under