Allows external rendering of other filetypes 2 (#8300)
Allows external rendering of other filetypes 2 (#8300)

* allow external rendering of other filetypes

fixes #4996 and #7614 
allows rendering of non-tex files, or otherwise accounted for filetypes

* Moves flie-size check before read()

And performs gofmt -s

* Only reads if markType is detected

typeless/gitea,typeless/gitea,lafriks/gitea,sapk-fork/gitea,sapk-fork/gitea,sapk-fork/gitea,cez81/gitea,lafriks/gitea,vdbt/gitea,go-gitea/gitea,lafriks/gitea,typeless/gitea,vCaesar/gitea,cez81/gitea,vdbt/gitea,vCaesar/gitea,go-gitea/gitea,typeless/gitea,sapk-fork/gitea,go-gitea/gitea,cez81/gitea