Documentation: Use Sphinx's extlinks to cut down on repeated URLs. Merge Administration and Maintenance topics. Add database conversion chapter. Unify the header format of all recent release notes. Fix :doc: references.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

docs/conf.py

@@ -33,7 +33,9 @@ sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "_ext"))
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
 #extensions = ['sphinx.ext.autodoc', 'sphinx.ext.viewcode']
 #extensions = ["djangodocs", "sphinx.ext.intersphinx"]
-extensions = ['sphinxcontrib.blockdiag', 'sphinxcontrib.spelling']
+extensions = [
+    'sphinx.ext.extlinks', 'sphinxcontrib.blockdiag', 'sphinxcontrib.spelling'
+]
 
 blockdiag_antialias = True
 blockdiag_html_image_format = "SVG"
@@ -233,34 +235,17 @@ man_pages = [
 
 html_theme = 'sphinx_rtd_theme'
 
-from docutils import nodes, utils
-from docutils.parsers.rst import roles
-from sphinx.roles import _amp_re
-
-def patched_menusel_role(typ, rawtext, text, lineno, inliner, options={}, content=[]):
-    text = utils.unescape(text)
-    if typ == 'menuselection':
-        text = text.replace('-->', 'qwe\N{RIGHTWARDS ARROW}')  # Here is the patch
-    spans = _amp_re.split(text)
-
-    node = nodes.emphasis(rawtext=rawtext)
-    for i, span in enumerate(spans):
-        span = span.replace('&&', '&')
-        if i == 0:
-            if len(span) > 0:
-                textnode = nodes.Text(span)
-                node += textnode
-            continue
-        accel_node = nodes.inline()
-        letter_node = nodes.Text(span[0])
-        accel_node += letter_node
-        accel_node['classes'].append('accelerator')
-        node += accel_node
-        textnode = nodes.Text(span[1:])
-        node += textnode
-
-    node['classes'].append(typ)
-    return [node], []
-
-# Use 'patched_menusel_role' function for processing the 'menuselection' role
-roles.register_local_role('menuselection', patched_menusel_role)
+# -- External links --
+extlinks = {
+    'django-docs': (
+        'https://docs.djangoproject.com/en/{}/%s'.format(
+            mayan.__django_version__
+        ), 'Django documentation section: '
+    ),
+    'github-issue': (
+        'https://github.com/mayan-edms/mayan-edms/issues/%s', 'GitHub issue #'
+    ),
+    'gitlab-issue': (
+        'https://gitlab.com/mayan-edms/mayan-edms/issues/%s', 'GitLab issue #'
+    )
+}