I've been using Texmaker for ~5 years now and prefer it over other editors because of its flexibility.
Is there a way to auto-indent LaTeX code in TeXmaker so that the code becomes more manageable ?
Upvoted comment converted to answer to clear off the Q from unanswered list.
Such indentation and code beautification is made possible with latexindent tool by cmhughes which can be integrated into TeXmaker by user command and automated by arara. As such TeXmaker does not have any full pledged indentation.
Also one might need to change settings of TeXmaker to notice the indentation changes done by