Proposal: Detail linting recommendation per language

### Description

The current guideline suggests to use linting, but not the specific linting rules to apply. Linting rules may be subjective per project, but the goal of systemic linting is to ensure samples of a given language have consistency.

Let's add written guidelines to the linting rules, and possibly references to the tools and configuration we recommend.

Thanks to @bshaffer for noting the opportunity to improve this guideline.

### Impact

The will not impact existing repositories that correctly implement linting, but will make this guideline much more actionable in setting up new repositories.

### Challenge

TBD

### Implementation

* [ ] Java
* [x] Node.js
* [ ] Python
* [ ] Go
* [ ] C#
* [ ] Ruby
* [x] PHP