[readme] add TOC and conform to linter suggestions

README.md

@@ -7,21 +7,35 @@
 ![Tests Status](./docs/tests-badge.svg)
 ![Coverage Status](./docs/coverage-badge.svg)
 
+<!--toc:start-->
+
+- [Development](#development)
+  - [Getting started](#getting-started)
+    - [Python](#python)
+    - [PostgreSQL](#postgresql)
+    - [Get the code](#get-the-code)
+  - [Making changes](#making-changes)
+  - [Using the App](#using-the-app)
+- [Dependency management](#dependency-management)
+  - [Installing dependencies](#installing-dependencies)
+
+<!--toc:end-->
+
 ## Development
 
 This project makes use of several tools:
 
-* [direnv] is used to set up environment variables and activate the virtualenv. I
+- [direnv] is used to set up environment variables and activate the virtualenv. I
 recommend installing it and integrate it into your favourite shell.
-* [just] is used as a task runner.
-* [woodpecker-cli] is used to lint `.woodpecker/workflow.yaml`. It is available
+- [just] is used as a task runner.
+- [woodpecker-cli] is used to lint `.woodpecker/workflow.yaml`. It is available
 from [homebrew].
-* [pytest] is the test runner. Invoke it using `just test` (any arguments will be
+- [pytest] is the test runner. Invoke it using `just test` (any arguments will be
 passed through to pytest).
   Several pytest-plugins are used:
-  * [hypothesis]
-  * [pytest-django]
-  * [pytest-cov]
+  - [hypothesis]
+  - [pytest-django]
+  - [pytest-cov]
 
 ### Getting started