Summary:
Set up a Jenkins pipeline to build the manual as PDF:
* Add a Dockerfile to create a Focal Fossa build environment
* Add a Jenkinsfile for the Manual pipeline
* Publish the PDF
Due to unicode characters in the source, LaTeX fails to build:
* Changed the engine to xelatex
* Added some LaTeX configurations for the PDF build
Ref T109
Test Plan:
1. Setup Jenkins
1.1 Create a new Pipeline
1.1.1 Definition => Pipeline script from SCM
1.1.1 SCM => Git
1.1.1 Repositories => https://phab.lubuntu.me/source/manual/
1.2. Install plugins
1.2.1 Docker plugin and Docker Pipeline plugin
1.2.2 HTML Publisher plugin
2. Install Docker on the Jenkins server
3. Manually start the job
4. Check, that there is a "Lubuntu Manual" link in the Job view, when the build was successful
Reviewers: lynorian, tsimonq2, teward
Reviewed By: tsimonq2
Maniphest Tasks: T109
Differential Revision: https://phab.lubuntu.me/D102
