Expose default treeadapter

[jacobbogers]

I can now do:

const ta = require('parse5/lib/tree-adapters/default');

but aesthetically not gorgeous like the rest of this wonderful code and a bit of a hacky , could the default parser be exported as require('parse5/adaptor-default') or require(parse5/default-adaptor); or const { adapter } = require('parse5'); and expose it officially this way

My 2cts

[frank-dspeed]

@jacobbogers vote 4 my issue #307 :) i will refactor to clean esm and produce babel cjs compatible version
#308

[jacobbogers]

I think your proposal covers refactoring to ES2020 standard, but I just want expose "hidden" treeadapter, I will make PR for this, no worries, about your issue, lets discuss in your issue.

[frank-dspeed]

@jacobbogers i will refactor to ES2020 and compile down to what ever the consumer needs and that will expose everything as a module including the treeAdapter :)

import { treeAdapter } from 'es-parse5'