subprojects: Add a wrap for gst-docs

Preparing for building API documentation with hotdoc
6 jobs for master in 14 minutes and 59 seconds (queued for 1 second)
Status Name Job ID Coverage
  Preparation
passed gst indent #250931

00:00:17

passed manifest #250930

00:00:26

 
  Build
passed build fedora x86_64 #250932

00:06:14

passed build nodebug fedora x86_64 #250933

00:06:06

 
  Test
passed check fedora #250934

00:03:30

passed integration testsuites fedora #250935

00:08:17