[doc] improve documentation of make targets and ./manage script

BTW force modularization of the ./mange script into sub modules:

- utils/lib_sxng_data.sh
- utils/lib_sxng_node.sh
- utils/lib_sxng_static.sh
- utils/lib_sxng_test.sh
- utils/lib_sxng_themes.sh

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

docs/dev/quickstart.rst

@@ -7,8 +7,16 @@ Development Quickstart
 .. _npm: https://www.npmjs.com/
 .. _Node.js: https://nodejs.org/
 
-SearXNG loves developers, just clone and start hacking.  All the rest is done for
-you simply by using :ref:`make <makefile>`.
+
+.. sidebar:: further read
+
+   - :ref:`makefile`
+   - :ref:`buildhosts`
+
+SearXNG loves developers; Developers do not need to worry about tool chains, the
+usual developer tasks can be comfortably executed via :ref:`make <makefile>`.
+
+Don't hesitate, just clone SearXNG's sources and start hacking right now ..
 
 .. code:: bash
 
@@ -18,25 +26,23 @@ Here is how a minimal workflow looks like:
 
 1. *start* hacking
 2. *run* your code: :ref:`make run`
-3. *test* your code: :ref:`make test`
+3. *format & test* your code: :ref:`make format.python` and :ref:`make test`
 
 If you think at some point something fails, go back to *start*.  Otherwise,
 choose a meaningful commit message and we are happy to receive your pull
 request. To not end in *wild west* we have some directives, please pay attention
 to our ":ref:`how to contribute`" guideline.
 
-If you implement themes, you will need to setup a :ref:`make node.env` once:
+.. sidebar:: further read
 
-.. code:: bash
+   - :ref:`make nvm`
+   - :ref:`make themes`
 
-   make node.env
+If you implement themes, you will need to setup a :ref:`Node.js environment
+<make node.env>`: ``make node.env``
 
 Before you call *make run* (2.), you need to compile the modified styles and
-JavaScript:
-
-.. code:: bash
-
-   make themes.all
+JavaScript: ``make themes.all``
 
 Alternatively you can also compile selective the theme you have modified,
 e.g. the *simple* theme.
@@ -49,6 +55,10 @@ e.g. the *simple* theme.
 
    To get live builds while modifying CSS & JS use: ``LIVE_THEME=simple make run``
 
+.. sidebar:: further read
+
+   - :ref:`make static.build`
+
 If you finished your *tests* you can start to commit your changes.  To separate
 the modified source code from the build products first run: