Update Roadmap.html

[CodeWizrd001]

Added Links to VSCode Extension for Code Highlighting and Snippets for XSM and SPL

[itsfarseen]

@CodeWizrd001 it is better if we have an extra page to put all these extra stuff in.
That is stuff that are not official, but useful.
We will have a dedicated page to if anyone else want to implement goodies like this.
We can make it explicit that it is not officially supported so that people won't bug murali sir if any bug happens there.
Also we can properly credit the creators.
Could you or find someone to work out how to add a page like this?
I prefer to have it in this page: https://exposnitc.github.io/documentation.html as a new grid item right next to Roadmap's square.

[CodeWizrd001]

Yeah that seems reasonable
We could add a provision to useful tools