chore: convert core module to typescript (#260)

Co-authored-by: Xiaoji Chen <cxiaoji@gmail.com>

dev-docs/RFCs/math-monorepo-rfc.md

@@ -37,7 +37,7 @@ Using with math.gl `Vector3`:
 
 ```js
 import {Ellipsoid} from '@math.gl/geospatial';
-import {Vector3} from 'math.gl';
+import {Vector3} from '@math.gl/core';
 const cartesian = Ellipsoid.WSG84.cartographicToCartesian(new Vector3(lng, lat, z));
 ```
 

docs/upgrade-guide.md

@@ -1,5 +1,19 @@
 # Upgrade Guide
 
+## Upgrading to v3.6
+
+In version 3.6 the entire math.gl code base was converted to typescript (`.ts`).
+While the API itself has not changed, in some cases, the introduction of types
+made it harder to keep supporting some type signatures and overloads.
+
+Known changes
+- `Matrix4.lookAt()` - Now only accepts named parameters.
+- `SphericalCoordinates()` - Constructor is now more restrictive in terms of what parameters it accepts.
+
+Note that some omissions may be unintentional, feel free to report upgrade issues
+in the math.gl github repo.
+
+
 ## Upgrading to v3.0
 
 ### Matrix API changes

docs/whats-new.md

@@ -29,9 +29,13 @@
 
 Target Release Date: Q4, 2021
 
+Codebase has been fully converted to typescript. In general this means that users can expect
+the types exported from math.gl to be considerably improved, however in some function signatures
+are no longer supported. For details, consult the [upgrade guide](./upgrade-guide).
+
 **`@math.gl/types` (NEW)
 
-- New module that exports a couple of typescript types that simplify handling of e.g. numeric arrays.
+- New module that exports a few typescript types that e.g. generalize handling of numeric arrays.
 
 ## v3.5