doc: add tls.cert_chain_len docs v2

[jmtaylor90]

Ticket: #6386

Make sure these boxes are signed before submitting your Pull Request -- thank you.

• I have read the contributing guide lines at https://docs.suricata.io/en/latest/devguide/codebase/contributing/contribution-process.html
• I have signed the Open Information Security Foundation contribution agreement at https://suricata.io/about/contribution-agreement/
• I have updated the user guide (in doc/userguide/) to reflect the changes made (if applicable)

Link to redmine ticket:

https://redmine.openinfosecfoundation.org/issues/6386

Describe changes:

• Added ticket number to commit

Provide values to any of the below to override the defaults.

To use a pull request use a branch name like pr/N where N is the
pull request number.

Alternatively, SV_BRANCH may also be a link to an
OISF/suricata-verify pull-request.

SV_REPO=
SV_BRANCH=
SU_REPO=
SU_BRANCH=
LIBHTP_REPO=
LIBHTP_BRANCH=

[jufajardini]

Thanks for adding the ticket number to the commit!

Changes look good to me :)

[codecov]

Codecov Report

Merging #9597 (4b0a824) into master (1a132f4) will increase coverage by 0.04%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #9597      +/-   ##
==========================================
+ Coverage   82.28%   82.33%   +0.04%     
==========================================
  Files         968      968              
  Lines      274275   274275              
==========================================
+ Hits       225700   225822     +122     
+ Misses      48575    48453     -122     

Flag	Coverage Δ
fuzzcorpus	64.50% <ø> (+0.16%)	⬆️
suricata-verify	60.91% <ø> (-0.02%)	⬇️
unittests	62.87% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

[jmtaylor90]

Thanks for adding the ticket number to the commit!

Changes look good to me :)

Great! One thing I thought of as I was submitting this, do we want suricata-verify tests for this keyword? I don't see any currently.

[jufajardini]

Thanks for adding the ticket number to the commit!
Changes look good to me :)

Great! One thing I thought of as I was submitting this, do we want suricata-verify tests for this keyword? I don't see any currently.

That's definitely a yes from my end, as this adds coverage and examples.

[victorjulien]

Merged in #9637, thanks!