v2.7.1 - Markdown linting updates, pylint

Markdown

This is a very small release that fixes a bug in the lint-md markdown linting script. It was having trouble with finding itself when invoked via a symlink (/node_modules/.bin/lint-md --> /node_modules/mobify-code-style/docs/bin/lint-md).

We've switched the Markdown linting to use no-duplicate-headings-in-section (instead of no-duplicate-headings). There are times when a document does duplicate a header in different sections (especially when outlining the same series of steps for different platforms). This rule change allows duplicate headings as long as they don't occur in the same section.

Python

This update also includes some updates to Python styling and linting.