Asset improvements (#1557)

This PR does the following:
- Add `selfHosted.js`, which is a great option for users that wish to
self host the assets. Works well for both self hosting from the public
folder or via a CDN.
- Updates the docs for assets. We now have a dedicated page for assets
where all the options are more clearly explained. I also removed the
assets explanation from the main docs as the unpkg option should work
out of the box and setting up the assets is no longer necessary.
- Cleaned up the `refresh-assets` script. We now use common `types.d.ts`
file to define our types. All the other options then reuse them.
- Pulled out the `formatAssetUrl` into it's own file. It's now static an
no longer generated.
- `urls.d.ts`, `import.d.ts`, and newly added `selfhosted.d.ts` are now
also no longer generated as we can import the types from `types.d.ts`.
- You can now pass a subset of `assetUrls` to `<Tldraw />` and it will
override the default option with the passed in overrides. This makes it
easy to only customizes certain assets (only change the draw font as an
example).

### Change Type

- [x] `patch` — Bug Fix

packages/utils/api-report.md

@@ -130,6 +130,11 @@ export function promiseWithResolve<T>(): Promise<T> & {
 // @internal
 export function rafThrottle(fn: () => void): () => void;
 
+// @public (undocumented)
+export type RecursivePartial<T> = {
+    [P in keyof T]?: RecursivePartial<T[P]>;
+};
+
 // @public (undocumented)
 export type Result<T, E> = ErrorResult<E> | OkResult<T>;
 

packages/utils/src/index.ts

@@ -26,4 +26,5 @@ export {
 } from './lib/object'
 export { rafThrottle, throttledRaf } from './lib/raf'
 export { sortById } from './lib/sort'
+export type { RecursivePartial } from './lib/types'
 export { isDefined, isNonNull, isNonNullish, structuredClone } from './lib/value'

packages/utils/src/lib/types.ts

@@ -0,0 +1,4 @@
+/** @public */
+export type RecursivePartial<T> = {
+	[P in keyof T]?: RecursivePartial<T[P]>
+}