Check grammar mistakes in documntation

[jcubic]

I was just checking the documentation:

https://lips.js.org/docs/scheme-intro/input-output

And found few examples of missing "a" and "an" before nouns.

The task is to real whole documentation and correct any grammar (including above) that you can find.

[ArshadAriff]

Can i work on this @jcubic sir?

[jcubic]

@ArshadAriff yes, but note that there are probably not a lot of grammar mistakes because I used language tool when writing docs. But it seems that there are still small issues.

There is a need to check all the markdown files inside /docs/docs/ directory.