Fix docs warnings (#585)

Mostly around duplicate target names, fixed by using the anonymous link syntax on RST (two underscores).

Author: adamchainz

docs/aggregates.rst

@@ -21,8 +21,8 @@ The following can be imported from ``django_mysql.models``.
 
     Docs:
     `MySQL
-    <https://dev.mysql.com/doc/refman/en/group-by-functions.html#function_bit-and>`_ /
-    `MariaDB <https://mariadb.com/kb/en/mariadb/bit_and/>`_.
+    <https://dev.mysql.com/doc/refman/en/group-by-functions.html#function_bit-and>`__ /
+    `MariaDB <https://mariadb.com/kb/en/mariadb/bit_and/>`__.
 
     Example usage:
 
@@ -41,8 +41,8 @@ The following can be imported from ``django_mysql.models``.
 
     Docs:
     `MySQL
-    <https://dev.mysql.com/doc/refman/en/group-by-functions.html#function_bit-or>`_ /
-    `MariaDB <https://mariadb.com/kb/en/mariadb/bit_or/>`_.
+    <https://dev.mysql.com/doc/refman/en/group-by-functions.html#function_bit-or>`__ /
+    `MariaDB <https://mariadb.com/kb/en/mariadb/bit_or/>`__.
 
     Example usage:
 
@@ -61,8 +61,8 @@ The following can be imported from ``django_mysql.models``.
 
     Docs:
     `MySQL
-    <https://dev.mysql.com/doc/refman/en/group-by-functions.html#function_bit-xor>`_ /
-    `MariaDB <https://mariadb.com/kb/en/mariadb/bit_xor/>`_.
+    <https://dev.mysql.com/doc/refman/en/group-by-functions.html#function_bit-xor>`__ /
+    `MariaDB <https://mariadb.com/kb/en/mariadb/bit_xor/>`__.
 
     Example usage:
 
@@ -80,8 +80,8 @@ The following can be imported from ``django_mysql.models``.
     Useful mostly for bringing back lists of ids in a single query.
 
     Docs:
-    `MySQL <https://dev.mysql.com/doc/refman/en/group-by-functions.html#function_group-concat>`_ /
-    `MariaDB <https://mariadb.com/kb/en/mariadb/group_concat/>`_.
+    `MySQL <https://dev.mysql.com/doc/refman/en/group-by-functions.html#function_group-concat>`__ /
+    `MariaDB <https://mariadb.com/kb/en/mariadb/group_concat/>`__.
 
     Example usage:
 
@@ -101,8 +101,8 @@ The following can be imported from ``django_mysql.models``.
         increase it if you're using this for any sizeable groups.
 
         ``group_concat_max_len`` docs:
-        `MySQL <https://dev.mysql.com/doc/refman/en/server-system-variables.html#sysvar_group_concat_max_len>`_ /
-        `MariaDB <https://mariadb.com/kb/en/server-system-variables/#group_concat_max_len>`_.
+        `MySQL <https://dev.mysql.com/doc/refman/en/server-system-variables.html#sysvar_group_concat_max_len>`__ /
+        `MariaDB <https://mariadb.com/kb/en/server-system-variables/#group_concat_max_len>`__.
 
     Optional arguments:
 

docs/cache.rst

@@ -108,7 +108,7 @@ Multiple Databases
 If you use this with multiple databases, you'll also need to set up routing
 instructions for the cache table. This can be done with the same method
 that is described for ``DatabaseCache`` in the `Django manual
-<https://docs.djangoproject.com/en/1.8/topics/cache/#database-caching>`_, apart
+<https://docs.djangoproject.com/en/1.8/topics/cache/#database-caching>`__, apart
 from the application name is ``django_mysql``.
 
 .. note::
@@ -204,7 +204,7 @@ ways:
    ``cull()`` on all of your ``MySQLCache`` instances, or you can give it names
    to just cull those. For example, this:
 
-   .. code-block:: python
+   .. code-block:: console
 
        $ python manage.py cull_mysql_caches default other_cache
 

docs/checks.rst

@@ -29,8 +29,8 @@ truncation upon insertion, by escalating warnings into errors. It is strongly
 recommended you activate it.
 
 Docs:
-`MySQL <https://dev.mysql.com/doc/refman/en/sql-mode.html#sql-mode-strict>`_ /
-`MariaDB <https://mariadb.com/kb/en/mariadb/sql_mode/#strict-mode>`_.
+`MySQL <https://dev.mysql.com/doc/refman/en/sql-mode.html#sql-mode-strict>`__ /
+`MariaDB <https://mariadb.com/kb/en/mariadb/sql_mode/#strict-mode>`__.
 
 It is configured as part of ``sql_mode``, a system variable contains a list of
 comma-separated modes to activate. Please check the value of your install and
@@ -73,8 +73,8 @@ Normally this just affects per-table settings for compression. It's recommended
 you activate this, but it's not very likely to affect you if you don't.
 
 Docs:
-`MySQL <https://dev.mysql.com/doc/refman/en/innodb-parameters.html#sysvar_innodb_strict_mode>`_ /
-`MariaDB <https://mariadb.com/kb/en/mariadb/xtradbinnodb-strict-mode/>`_.
+`MySQL <https://dev.mysql.com/doc/refman/en/innodb-parameters.html#sysvar_innodb_strict_mode>`__ /
+`MariaDB <https://mariadb.com/kb/en/mariadb/xtradbinnodb-strict-mode/>`__.
 
 As above, the easiest way to set this is to add ``SET`` to ``init_command`` in
 your ``DATABASES`` setting:
@@ -115,8 +115,8 @@ you'll never see any of these 'supplementary' Unicode characters (note: it's
 very easy for users to type emoji on phone keyboards these days!).
 
 Docs:
-`MySQL <https://dev.mysql.com/doc/refman/en/charset-unicode-utf8mb4.html>`_ /
-`MariaDB <https://mariadb.com/kb/en/mariadb/unicode/>`_.
+`MySQL <https://dev.mysql.com/doc/refman/en/charset-unicode-utf8mb4.html>`__ /
+`MariaDB <https://mariadb.com/kb/en/mariadb/unicode/>`__.
 
 Also see this classic blogpost:
 `How to support full Unicode in MySQL databases <https://mathiasbynens.be/notes/mysql-utf8mb4>`_.
@@ -149,4 +149,4 @@ Note this does not transform the database, tables, and columns that already
 exist. Follow the examples in the 'How to' blog post link above to fix your
 database, tables, and character set. It's planned to add a command to
 Django-MySQL to help you do this, see
-`Issue 216 <https://github.com/adamchainz/django-mysql/issues/216>`_.
+`Issue 216 <https://github.com/adamchainz/django-mysql/issues/216>`__.