add typescript definitions

[giladgray]

Fixes #345

• add index.d.ts to popper package (and types entry in package.json)
• add a note in PULL_REQUEST_TEMPLATE to remind folks to keep this updated

[CLAassistant]

All committers have signed the CLA.

[giladgray]

@FezVrasta is there any work required to ensure the new index.d.ts file gets published to NPM? also, are you okay with placing it in the package root?

[giladgray]

@FezVrasta wow that CLA-assistant wants a lot of permissions! Why does it need to write to my public repos?

[FezVrasta]

Please don't remove the trailing whitespaces, they are meaningful in markdown

[giladgray]

my editor did that. but also this is a comment, so they're really not meaningful here: it is invisible in rendered output.

i much prefer using blank lines to create paragraphs in markdown (instead of the awkward trailing two spaces) because i always have my editor set to trim trailing whitespace.

[giladgray]

also blank lines are visible in source so i can tell immediately that you meant to have two paragraphs.

[FezVrasta]

Didn't you decide to maintain them yourself? If this is still the case is rephrase this to a "nice to have but not requiree action"

[giladgray]

i'll take responsibility for this file and be the first line of defense should something go wrong, but i think it's worth adding a comment like this so folks know it exists.

if someone forgets, or has trouble editing it, ping me for help. i'll amend the note to this effect.

[FezVrasta]

As stated previously, I don't want to lose contributions because someone gets scared reading he needs to know TypeScript to contribute.

If the point says "If you change the public API, it would be nice to try to update the TypeScript definitions accordingly. This is not required but will help a lot." (or something similar) then I'd be happy to merge this.

Otherwise, feel free to contribute to the definitely typed project, doing so you can keep the definitions up to date and be completely independent.

[giladgray]

I'd be wary of contributors changing the public API at will--probably not likely to happen often, but when it does then special attention will be essential anyway.

i'll update the message to be more accomodating

[giladgray]

@FezVrasta added a note about myself in PR template. let me know what else you'd like to see here. would be great to merge and ship a new release soon so I can consume it in Blueprint!

[FezVrasta]

ok it looks great now. I'm not sure how this new file you added gets read by TypeScript but:

1. Right now it will not be included in the npm package because we include only dist/*
2. If people import from dist/esm/popper.js should the new file be in that folder as well with the same name?
3. Same of point 2 applies for the umd build and the next/es build on the dist/ root directory

[giladgray]

The types entry in package.json tells TS compiler where to find typings, that's the only thing that matters.
Fair to add index.d.ts to files list then?

[FezVrasta]

Yes sure

[FezVrasta]

released as 1.11.0