Add extensions for ConTeXt
Add extensions for ConTeXt

[ConTeXt] is a macro language build on TeX (just as LaTeX is build on
TeX). It tends to use `.mkii` and `.mkiv` extensions to represent files used in
Mark II (MkII) version and Mark IV (MkIV) version of ConTeXt.

[ConTeXt]: http://wiki.contextgarden.net/

adamkaplan/linguist,a0viedo/linguist,tschf/linguist,JJ/linguist,PsichiX/linguist,erkyrath/linguist,phpsgi/linguist,SRI-CSL/linguist,sagar290/linguist,github/linguist,Mx7f/linguist,sideci-sample/sideci-sample-linguist,FStarLang/linguist,mcandre/linguist,steventhanna/linguist,sideci-sample/sideci-sample-linguist,alvarotrigo/linguist,stanhu/linguist,stanhu/linguist,ppaulweber/github-linguist,christop/linguist,kyoungrok0517/linguist,hcatlin/linguist,marcojonker/test,cybernet14/linguist,georgesuperman/linguist,github/linguist,ilyes14/linguist,yscho/linguist,Mailaender/linguist,nburkley/linguist,erkyrath/linguist,matt40k/linguist,seanders/linguist,cokeboL/linguist,jjatria/linguist,martynbm/linguist,Ocramius/linguist,hcatlin/linguist,MostAwesomeDude/linguist,alvarotrigo/linguist,blakeembrey/linguist,pcantrell/linguist,matt40k/linguist,bluebear94/linguist,thejameskyle/linguist,wcandillon/linguist,meunierfrederic/octocatlinguist,chiranjeevjain/linguist,BerkeleyTrue/linguist,whitj00/linguist,osorgin/linguist,manveru/linguist,ya7lelkom/linguist,erkyrath/linguist,mattn/linguist,pcantrell/linguist,thejameskyle/linguist,stanhu/linguist,jrnold/linguist,R4PaSs/linguist,CoderXpert/linguist,ppaulweber/github-linguist,ilyes14/linguist,whitj00/linguist,sebgod/linguist,osorgin/linguist,alitalia/linguist,pchaigno/linguist,douglas-larocca/linguist,c-lipka/linguist,stanhu/linguist,meunierfrederic/octocatlinguist,R4PaSs/linguist,erkyrath/linguist,pchaigno/linguist,MostAwesomeDude/linguist,FStarLang/linguist,cybernet14/linguist,yyx990803/linguist,georgesuperman/linguist,yyx990803/linguist,0a-/linguist,cokeboL/linguist,sebgod/linguist,igat259/linguist,davidzchen/linguist,martynbm/linguist,assimovt/ling-ist,phpsgi/linguist,yyx990803/linguist,JJ/linguist,CegepVictoriaville/linguist,maxogden/linguist,BerkeleyTrue/linguist,steventhanna/linguist,christop/linguist,ChaiScript/linguist,manveru/linguist,Mx7f/linguist,sebgod/linguist,github/linguist,JJ/linguist,douglas-larocca/linguist,iblech/linguist,seanders/linguist,JJ/linguist,mwpastore/linguist,pchaigno/linguist,MahmoudFayed/linguist,wcandillon/linguist,sagar290/linguist,ammaraskar/linguist,hcutler/linguist,MadcapJake/linguist,blakeembrey/linguist,nburkley/linguist,kyoungrok0517/linguist,jtbandes/linguist,davidzchen/linguist,scttnlsn/linguist,SRI-CSL/linguist,PsichiX/linguist,mattn/linguist,ammaraskar/linguist,marcojonker/test,mwpastore/linguist,CegepVictoriaville/linguist,a0viedo/linguist,chiranjeevjain/linguist,hcutler/linguist,tschf/linguist,iblech/linguist,Rockyspade/linguist,github/linguist,MahmoudFayed/linguist,jjatria/linguist,yyx990803/linguist,c-lipka/linguist,jtbandes/linguist,meunierfrederic/octocatlinguist,jrnold/linguist,anhongyue/test222,assimovt/ling-ist,mcandre/linguist,pchaigno/linguist,0a-/linguist,yscho/linguist,ya7lelkom/linguist,scttnlsn/linguist,Rockyspade/linguist,CoderXpert/linguist,MadcapJake/linguist,sebgod/linguist,kr/linguist,kr/linguist,anhongyue/test222,adamkaplan/linguist,bluebear94/linguist,alitalia/linguist