Before this change, the docs failed to build with the following
error:

ImportError: cannot import name 'environmentfilter' from 'jinja2'

A fix to this problem is to explicitly pin Jinja2 version.

(cherry picked from commit cdaf75a)

docs: update dynamic slug

Add back index.md

Move custom slug to a separate PR

Fix typo

(cherry picked from commit 8feeb20)

Add Java Driver 4.x branches to the list of generated documentation
and bump the LATEST_VERSION variable.

(cherry picked from commit 76f7715)

(cherry picked from commit d2e261b)

Fix javadoc redirect

Fix

(cherry picked from commit a9fcffb)

(cherry picked from commit 7399a0a)

The links in our documentation have a hardcoded version number in them:

https://java-driver.docs.scylladb.com/scylla-3.11.2.x/api/
https://docs.datastax.com/en/drivers/java/3.11/com/datastax/driver/core/Cluster.html

Therefore, a replacement rule is needed to replace the version to a
correct version for a specific driver version we render the docs for.

Before this change, only datastax links were replaced. After this
change, java-driver.docs.scylladb.com links are also replaced.

(cherry picked from commit 8cd4d8e)

(cherry picked from commit 511573f)

Add 4.14.1.x and 4.15.0.x releases to the list of versions to generate
the docs for.

(cherry picked from commit d296895)

docs: update conf.py

docs: update conf.py

docs: Update conf.py

docs: update conf.py

docs: Update conf.py

docs: update conf.py
(cherry picked from commit 0d1f1c4)

docs: test

docs: add skip warnings option
(cherry picked from commit 2601b78)

(cherry picked from commit 51ff0d5)

(cherry picked from commit 7ab2a8f)

Signed-off-by: Kefu Chai <[email protected]>
(cherry picked from commit 6a5d3a7)

(cherry picked from commit 8dea9e2)

(cherry picked from commit 9eedcac)

this change is not cherry-picked from 4.x, as it is specific to
scylla-3.x branch.

Signed-off-by: Kefu Chai <[email protected]>

(cherry picked from commit efe5101)

to silence the warning from sphinx, as we have two "Dropwizard
Metrics" sections in manual/core/metrics/index.md:

```
/home/kefu/dev/scylla-java-driver/docs/_source/manual/core/metrics/index.md:291: WARNING: duplicate label manual/core/metrics/index:dropwizard metrics, other instance in /home/kefu/dev/scyll
a-java-driver/docs/_source/manual/core/metrics/index.md
```

and the warning breaks the "make test". so let's suppress the warning
at this moment.

Signed-off-by: Kefu Chai <[email protected]>

it should start with three backticks not four of them. otherwise
sphinx warns like:

```
/home/kefu/dev/scylla-java-driver/docs/_source/manual/mapper/daos/getentity/index.md:111: WARNING: Lexing literal_block '@GetEntity\nProduct asProduct(Row row);\n\n@GetEntity\nProduct firstR
owAsProduct(ResultSet resultSet);\n```\n\n' as "java" resulted in an error at token: '`'. Retrying in relaxed mode.
```

in this change, let's use three backticks. and the warning disappears.

Signed-off-by: Kefu Chai <[email protected]>