doc: proofread of the all reST sources (no content change)

Normalize reST sources with best practice and KISS in mind.

to name a few points:

- simplify reST tables
- make use of ``literal`` markup for monospace rendering
- fix code-blocks for better rendering in HTML
- normalize section header markup
- limit all lines to a maximum of 79 characters
- add option -H to the sudo command used in code blocks
- drop useless indentation of lists
- ...

[1] https://www.sphinx-doc.org/en/master/usage/restructuredtext/basics.html

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

docs/dev/quickstart.rst

@@ -1,17 +1,18 @@
 .. _devquickstart:
 
+======================
 Development Quickstart
-----------------------
+======================
 
-This quickstart guide gets your environment set up with searx. Furthermore, it gives a
-short introduction to the new manage.sh script.
+This quickstart guide gets your environment set up with searx.  Furthermore, it
+gives a short introduction to the ``manage.sh`` script.
 
 How to setup your development environment
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+=========================================
 
-First, clone the source code of searx to the desired folder. In this case the source
-is cloned to ~/myprojects/searx. Then create and activate the searx-ve
-virtualenv and install the required packages using manage.sh.
+First, clone the source code of searx to the desired folder.  In this case the
+source is cloned to ``~/myprojects/searx``.  Then create and activate the
+searx-ve virtualenv and install the required packages using manage.sh.
 
 .. code:: sh
 
@@ -24,85 +25,86 @@ virtualenv and install the required packages using manage.sh.
 
 
 How to run tests
-~~~~~~~~~~~~~~~~
+================
 
-Tests can be run using the manage.sh script.
-
-Following tests and checks are available:
+Tests can be run using the ``manage.sh`` script.  Following tests and checks are
+available:
 
 - Unit tests
-
 - Selenium tests
-
 - PEP8 validation
-
 - Unit test coverage check
 
 For example unit tests are run with the command below:
 
 .. code:: sh
 
-    ./manage.sh unit_tests
+   ./manage.sh unit_tests
 
-For further test options, please consult the help of the manage.sh script.
+For further test options, please consult the help of the ``manage.sh`` script.
 
 
 How to compile styles and javascript
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+====================================
+
+.. _less: http://lesscss.org/
+.. _NodeJS: https://nodejs.org
 
 How to build styles
-^^^^^^^^^^^^^^^^^^^
+-------------------
 
-Less is required to build the styles of searx. Less can be installed using either NodeJS or Apt.
+Less_ is required to build the styles of searx.  Less_ can be installed using
+either NodeJS_ or Apt.
 
 .. code:: sh
 
-    sudo apt-get install nodejs
-    sudo npm install -g less
-
+   sudo -H apt-get install nodejs
+   sudo -H npm install -g less
 
 OR
 
 .. code:: sh
 
-    sudo apt-get install node-less
+   sudo -H apt-get install node-less
 
-After satisfying the requirements styles can be build using manage.sh
+After satisfying the requirements styles can be build using ``manage.sh``
 
 .. code:: sh
 
-    ./manage.sh styles
+   ./manage.sh styles
 
 
 How to build the source of the oscar theme
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+==========================================
 
-Grunt must be installed in order to build the javascript sources. It depends on NodeJS, so first
-Node has to be installed.
+.. _grunt: https://gruntjs.com/
+
+Grunt_ must be installed in order to build the javascript sources. It depends on
+NodeJS, so first Node has to be installed.
 
 .. code:: sh
 
-    sudo apt-get install nodejs
-    sudo npm install -g grunt-cli
+   sudo -H apt-get install nodejs
+   sudo -H npm install -g grunt-cli
 
-After installing grunt, the files can be built using the following command: 
+After installing grunt, the files can be built using the following command:
 
 .. code:: sh
 
-    ./manage.sh grunt_build
-
+   ./manage.sh grunt_build
 
 
 Tips for debugging/development
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+==============================
 
-1. Turn on debug logging
-    Whether you are working on a new engine or trying to eliminate a bug, it is always a good idea
-    to turn on debug logging. When debug logging is enabled a stack trace appears,
-    instead of the cryptic ``Internal Server Error`` message. It can be turned on by setting
-    ``debug: False`` to ``debug: True`` in settings.yml.
+Turn on debug logging
+  Whether you are working on a new engine or trying to eliminate a bug, it is
+  always a good idea to turn on debug logging.  When debug logging is enabled a
+  stack trace appears, instead of the cryptic ``Internal Server Error``
+  message. It can be turned on by setting ``debug: False`` to ``debug: True`` in
+  :origin:`settings.yml <searx/settings.yml>`.
 
-2. Run ``./manage.sh tests`` before creating a PR.
-    Failing build on Travis is common because of PEP8 checks. So a new commit must be created
-    containing these format fixes. This phase can be skipped if ``./manage.sh tests`` is run
-    locally before creating a PR.
+Run ``./manage.sh tests`` before creating a PR.
+  Failing build on Travis is common because of PEP8 checks.  So a new commit
+  must be created containing these format fixes.  This phase can be skipped if
+  ``./manage.sh tests`` is run locally before creating a PR.