Provide experimental, automated TypeScript declaration lovell#472

Author: lovell

CONTRIBUTING.md

@@ -43,6 +43,7 @@ Any change that modifies the existing public API should be added to the relevant
 | ------: | :--------- |
 | v0.17.0 | quill      |
 | v0.18.0 | ridge      |
+| v0.19.0 | suit       |
 
 Please squash your changes into a single commit using a command like `git rebase -i upstream/<wip-branch>`.
 
@@ -65,13 +66,18 @@ By way of example, the [bilinearInterpolation method](https://github.com/lovell/
 ## Documentation
 
 The public API is documented with [JSDoc](http://usejsdoc.org/) annotated comments.
-These can be converted to Markdown by running:
 
+These can be converted to Markdown by running:
 ```sh
 npm run docs
 ```
 
-Please include documentation updates in any Pull Request that modifies the public API.
+The `types.d.ts` TypeScript declaration can be generated by running:
+```sh
+npm run types
+```
+
+Please include documentation and TypeScript declaration updates in any Pull Request that modifies the public API.
 
 ## Run the tests
 

docs/changelog.md

@@ -15,6 +15,10 @@ Requires libvips v8.4.2.
   Access to these is now via output format functions, for example `quality(n)`
     is now `jpeg({quality: n})` and/or `webp({quality: n})`.
 
+* Provide experimental, automated TypeScript declaration.
+  [#472](https://github.com/lovell/sharp/issues/472)
+  [@davidreher](https://github.com/davidreher)
+
 * Expose libvips' "centre" resize option to mimic \*magick's +0.5px convention.
   [#568](https://github.com/lovell/sharp/issues/568)