Bnf diagram updates (#242)

Updated BNF diagrams include:
* updates to data types
* added missing statements
* clarified CREATE TABLE which was missing required `_id` column
* updated help-on-help for the bnf diagram creation
* added bash script to automate

Please let me know if there's anything [missing | borked | something
else]. Or just make the fixes yourself :)

Author: ljsinclair