Should flag non-comparative adjectives used with "than"

I've noticed this a few times lately. Here's one from just now:

> Graydon Hoare's impact on the language is **marginal than** that of Chris Lattner, the originator (also, Hoare joined the team much later)

The fix is to suggest adding the missing "more". Or probably checking for an -er inflected form in the dictionary.

Search the Rust grammar-checking rules for comparative constructions involving “than,” then inspect how adjective forms are represented in the dictionary. Done means the checker flags a non-comparative adjective such as “marginal than” and suggests adding “more,” while accounting for valid -er forms if supported.

Written by the indexing model from the issue text.