Use a default export for UMD module

[jonkoops]

Creates an alias for jwtDecode as the default export for UMD modules. Since users of the UMD module are very unlikely to migrate this will give them maximum compatibility with previous versions.

[jonkoops]

Going to add some documentation for this one, converting this to a draft.

[jonkoops]

So for users using the UMD version (either globals, or AMD) the following migration steps would apply:

Globals

The global jwt_decode function has been renamed to jwtDecode, this matches the casing used internally as well.

Before

<script src="jwt-decode.js"></script>
<script>
    const token = "eyJhsw5c";
    const decoded = jwt_decode(token);
</script>

After

<script src="jwt-decode.js"></script>
<script>
    const token = "eyJhsw5c";
    const decoded = jwtDecode(token);
</script>

AMD

The AMD module name has been renamed from jwt_decode to jwt-decode, this matches the name of the NPM package.

Before

<script src="jwt-decode.js"></script>
<script>
  define(["jwt_decode"], (jwtDecode) => {
    const token = "eyJhsw5c";
    const decoded = jwtDecode(token);
  });
</script>

After

<script src="jwt-decode.js"></script>
<script>
  define(["jwt-decode"], (jwtDecode) => {
    const token = "eyJhsw5c";
    const decoded = jwtDecode(token);
  });
</script>

@frederikprijck do you feel these changes make sense? Alternatively, we can keep things as they were before for maximum backwards compatibility. Can go either way as far as I am concerned.

[frederikprijck]

I would stick to what we had for AMD, changing UMD makes sense to me. I feel its unneccesary to have amd users have to make that change when it's working fine today, that wasn't the intention of the new major to begin with.

[jonkoops]

Yeah, I have to agree with that. I've reverted this back so that it should be 1-1 backwards compatible with what was before.

I would stick to what we had for AMD, changing UMD makes sense to me.

Not quite sure what you mean here. Just to clarify AMD is a sub-set of UMD, UMD attempts to make AMD and CommonJS interoperable with each other.

What exactly do you mean by "changing UMD makes sense to me"? Are you perhaps referring to the global?