build: sync common files from github_organization_management repository

Author: metworkbot

README.md

@@ -12,6 +12,37 @@
 
 
 
+## What is it ?
+
+This is a [jinja2](http://jinja.pocoo.org/) extension to access to system
+environment variables. It is usefull if you have dynamically generated
+variable names.
+
+## Syntax
+
+The syntax is `{{ 'ENV_VAR'|getenv }}` to access to the `ENV_VAR` environment
+variable. Don't forget the quotes around `ENV_VAR` !
+
+If you want to provide a default value to avoid an exception if the corresponding
+environment variable does not exist, you can use the following syntax:
+`{{ 'ENV_VAR'|getenv('default_value') }}`.
+
+## Examples
+
+```python
+
+from jinja2 import Template, Environment
+
+# We load the extension in a jinja2 Environment
+env = Environment(extensions=["jinja2_getenv_extension.GetenvExtension"])
+
+# For the example, we use a template from a simple string
+template = env.from_string("the value of HOME environment variable is: "
+                           "{{ 'HOME'|getenv }}")
+result = template.render()
+
+# [...]
+```