message: Add potential hueristics for the README
diff: @@ -51,18 +51,45 @@ The common steps to send a pull request are:
  3. Update the files in the `baselines` folder using the newly generated files
  under `generated` folder (`npm run baseline-accept`).
  -### When should a DOM API be included here?
  +### What are the TypeScript team's heuristics for PRs to the DOM APIs
  -A feature is considered highly experimental if a DOM API lacks multiple implementations or a formal specification from W3C or WHATWG. Such a feature belongs on [DefinitelyTyped](https://github.com/DefinitelyTyped/DefinitelyTyped#readme).
  -When it gets multiple implementations and a proper specification, it can be added here and removed from DefinitelyTyped.
  +Changes to this repo can have pretty drastic ecosystem effects, because these types are included by default in TypeScript.
  +Due to this, we tend to be quite conservative with our approach to introducing changes.
  +To give you a sense of whether we will accept changes, you can use these heuristics to know up-front if we'll be open to merging.
  +#### Fixes
  +
  +> For example, changing a type on a field, or nullability references
  +
  +- Does the PR show examples of the changes being used in spec examples or reputable websites like MDN?
  +- Did this change come from an IDL update?
  +- Does the change appear to be high-impact on a well-used API?
  +
  +#### Additions
  +
  +> For example, adding a new spec or subsection via a new or updated IDL file
  +
  +- Does the new objects or fields show up in [mdn/browser-compat-data](https://github.com/mdn/browser-compat-data)? If not, it's likely too soon
  +- What stage of the [W3C process](https://en.wikipedia.org/wiki/World_Wide_Web_Consortium#Specification_maturation) is the proposal for these changes: We aim for Proposed recommendation, but can accept Candidate recommendation for stable looking proposals.
  +- Are the additions available in at least two of Firefox, Safari and Chromium?
  +- Could any types added at the global scope have naming conflicts?
  +- Are the features going to be used by a lot of people?
  +
  +#### Removals
  +
  +> For example, removing a browser-specific section of code
  +
  +- Do the remove objects or fields show up in [mdn/browser-compat-data](https://github.com/mdn/browser-compat-data)? If so, are they marked as deprecated?
  +- Does an internet search for the fields show results in blogs/recommendations?
  +- When was the deprecation (this can be hard to find) but was it at least 2 years ago if so?
  +
  +# This repo
  ## Code Structure
  - `src/index.ts`: handles the emitting of the `.d.ts` files.
  - `src/test.ts`: verifies the output by comparing the `generated/` and `baseline/` contents.
  -
  ## Input Files
  - `browser.webidl.preprocessed.json`: a JSON file generated by Microsoft Edge. **Do not edit this file**.
  