Use straxen documentation building functions to avoid duplicated codes

[dachengx]

Before you submit this PR: make sure to put all XENONnT specific information in a wiki-note as the repo is publicly accessible

Depends on XENONnT/straxen#1380

What does the code in this PR do / what does it improve?

Can you briefly describe how it works?

Can you give a minimal working example (or illustrate with a figure)?

Please include the following if applicable:

• Update the docstring(s)
• Bump plugin version(s)
• Update the documentation
• Tests to check the (new) code is working as desired.
• Does it solve one of the GitHub open issues?

[coveralls]

Pull Request Test Coverage Report for Build 9114118464

Details

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.007%) to 78.007%

---

Totals
Change from base Build 9109329114:	0.007%
Covered Lines:	2302
Relevant Lines:	2951

---

💛 - Coveralls

[dachengx]

Since this is rather trivial, let me merge it. :)