Pandoc 2.13 compatible [with Gradle]

Readme updates.

Pandoc 2.13 [with Gradle]

This release uses Gradle as the build tool which makes everything more robust and faster.

Pandoc 2.13 compatible

v1.3.0

Merge branch 'master' of https://github.com/gabyx/TechnicalMarkdown

Pandoc 2.11.0.4 compatible

Improvements contain:

• tested with pandoc 2.11.0.4, panflute 2.0.5, pandoc-crossref v0.3.8.3
• tables (added some table examples, more to come -> + how to do special stuff
• latexmk fixes (clean up files)
• filters (lua and python)
• documentation