Backport to 6.1: mutliple doc changes (elastic#5849 elastic#5867 elas…

…tic#5887 elastic#5890) (elastic#5895)

* Document that Npcap must be installed in WinPCap compatible mode

* Remove references to [type] field

* Fix typo in breaking changes doc

* Fix run command

Close changelog for 6.1.0 release (elastic#5853)

* Close changelog for 6.1.0 release

* Added PB TLS to the changelog

* Windows service in changelog

Fix "queue" typo

Fixed docker diskio bug due to reseting of map. (elastic#5582) (elast…

…ic#5705)

* Fixed docker diskio bug due to reseting of map.

Fixes elastic#5568

Fix typo in Running on Kubernetes docs (elastic#5529) (elastic#5530)

(cherry picked from commit 8e94daa)

Fix missing length check in PgSQL (elastic#5457) (elastic#5480)

There was a length check missing.

(cherry picked from commit aeca657)

Close changelog for RC2 (elastic#5417)

Also updated the testing env.

Bump version to 5.6.3 in the 5.6 branch

Cherry-pick elastic#5189 to 6.0: cms_get and cmd_set mixed up in memc…

…ached module (elastic#5233)

Cherry-pick of PR elastic#5189 to 6.0 branch. Original message: 

I just created this here and thought to look at the code.

https://discuss.elastic.co/t/metricbeat-memcached-module-seems-to-mix-up-memcached-stats-cmd-get-and-memcached-stats-cmd-set/100732

[DOCS] Update link to certgen command