Remove more unused pages that can also be found on the wiki

src/docs/chapter/other/Jens_Bendisposto_Conferences.adoc

src/docs/chapter/other/Jens_Bendisposto_Model_Checkers.adoc

src/docs/chapter/reference/01_ABZ14.adoc

src/docs/chapter/reference/02_ABZ16.adoc

src/docs/chapter/reference/03_FormalPrototyping.adoc

src/docs/chapter/reference/04_ProjectionDiagram.adoc

src/docs/chapter/reference/05_Sefm2015.adoc