feat: add createMarkdown() factory to expose the compiler and parser

This allows for direct use of the markdown-to-jsx AST if it's preferable
for your use case to retain full control over output.

refactor: isolate React rendering rules

chore: upgrade dependencies

refactor: consolidate formatted text rules

chore: update dependencies

refactor: react 16

refactor: remove top-level compiler export

refactor: moving things around

chore: update benchmark

refactor: improve typings

refactor: refactor rules into tuple array, add disable/enableRules

feat: add custom rule support

forward-port fixes from 7.x

.changeset/dry-melons-press.md

@@ -0,0 +1,5 @@
+---
+'markdown-to-jsx': major
+---
+
+Bump minimum React version to 16+. `markdown-to-jsx` can now return strings directly without needing a wrapper unless forced via `options.forceWrapper`.

.changeset/five-frogs-repair.md

@@ -0,0 +1,5 @@
+---
+'markdown-to-jsx': minor
+---
+
+Add `options.enableRules` and `options.disableRules`; this allows for individual syntaxes to be conditionally switched on/off as desired.

.changeset/sour-llamas-develop.md

@@ -0,0 +1,5 @@
+---
+'markdown-to-jsx': minor
+---
+
+Add `options.customRules`, this allows for novel functionality to be implemented in tandem with `options.renderRule`.

.changeset/spicy-cherries-suffer.md

@@ -0,0 +1,16 @@
+---
+'markdown-to-jsx': major
+---
+
+Introduce the `createMarkdown(options)` factory function. This factory wraps and replaces the prior `compiler(input, options)` top-level export, while also exposing the AST parser directly for ✨ advanced use cases ✨.
+
+```tsx
+import { createMarkdown } from 'markdown-to-jsx'
+
+// parser = receive AST without going directly to React, allows for complete override
+// compiler = parser + React output (the equivalent of using the `Markdown` component)
+// Markdown = React component for convenience
+const { Markdown, compiler, parser } = createMarkdown({
+  /* any options here */
+})
+```