EML 2.2.0 Update

After EML 2.2.0 release on 2019/09/13, MetaShARK was updated in two major modules: Documentation and About.

• Documentation is now up-to-date with the one provided through XSD files. Note these files do not provide high-level nodes documentation. To remedy to this lack, there is now an external link to check the original documentation. Also note the original documentation has the advantage to show schemas of the modules.
• About module was filled in with Bibtex files references. This was performed by adding another package (RefManageR). The bibliography files are part of the Elie Arnaud's Master memoir's bibliography divided in three categories: actors (for active people and parties contributing to ecological metadata having helped to developp this app), informatics (for computer material and methods) and ecology (for ecological and fundamental material and methods).