Improved Types (#4119)

* Experimental release to see if CustomTypes holds up through a publish

* Add experimental release script

* Fix lint

* v0.60.5-alpha.0

* Allow null properties in setNodes

* v0.60.6-alpha.0

* Revert null properties on Transforms.setNodes

* v0.60.7-alpha.0

* Update examples to use custom Element and Text with discriminated unions

* Add documentation for using TypeScript improvements

* Be explicit about typescript version in package.json

* Force lerna bootstrap to fix build issues on CI and fix a few type examples

* Add slate devDependencies with * back

* v0.60.7

* Switch to a non prerelease version to fix lerna not linking in root

* Add documentation for not using prerelease versions and on how to create experimental releases

* Try removing lerna bootstrap and see if it works

packages/slate-hyperscript/package.json

@@ -1,7 +1,7 @@
 {
   "name": "slate-hyperscript",
   "description": "A hyperscript helper for creating Slate documents.",
-  "version": "0.60.4",
+  "version": "0.60.7",
   "license": "MIT",
   "repository": "git://github.com/ianstormtaylor/slate.git",
   "main": "dist/index.js",
@@ -17,7 +17,7 @@
     "is-plain-object": "^3.0.0"
   },
   "devDependencies": {
-    "slate": "^0.60.4"
+    "slate": "^0.60.7"
   },
   "peerDependencies": {
     "slate": ">=0.55.0"