Added Implementation Details
Merge https://github.com/igniting/ada-compiler

Conflicts:
	doc/documentation.pdf
	doc/documentation.tex
Merge branch 'master' of https://github.com/igniting/ada-compiler
Removed Keyword NULL and begin
Added name partially
Merge https://github.com/igniting/ada-compiler

Conflicts:
	lexer.l
	parser.y
[Grammer for aggregates section 4.3RM-Final]
Added grammar for expression
Did section 4.1 & 4.2
Merge branch 'master' of github.com:atiquefiroz/ada-compiler

Conflicts:
	parser.y
Merge branch 'master' of github.com:pranjals16/ada-compiler

Conflicts:
	parser.y
Minor changes in merge