README.md: promote dom/v2 API stability

The dom/v2 API tried to stay as close as possible to its original API,
but reimplemented on top of syscall/js API for increased compatibility.
This happened 4 years ago (see PR #69).

The "Alpha, more API changes may be done soon" stage was meant give us
room to make significant changes in case we needed to. Given how much
time has passed and it's been working okay, we're way past that stage
and at a point where significant breaking API changes would not happen
in v2. Update the README to say that now, even if it's way overdue.

Also update documentation links while here.

Author: dmitshur

README.md

@@ -4,9 +4,9 @@ Package dom provides Go bindings for the JavaScript DOM APIs.
 
 ## Version 2
 
-**API Status:** Alpha, more API changes may be done soon
+**API Status:** Stable, changes only due to DOM being a moving target
 
-Version 2 of package dom is implemented on top of the [`syscall/js`](https://godoc.org/syscall/js) API and supports both Go WebAssembly and GopherJS.
+Version 2 of package dom is implemented on top of the [`syscall/js`](https://go.dev/pkg/syscall/js) API and supports both Go WebAssembly and GopherJS.
 
 It provides an API that is as close as possible to v1, with the following neccessary changes:
 
@@ -20,18 +20,18 @@ It provides an API that is as close as possible to v1, with the following necces
 
 ### Documentation
 
-For documentation, see https://godoc.org/honnef.co/go/js/dom/v2.
+For documentation, see https://pkg.go.dev/honnef.co/go/js/dom/v2.
 
 ## Version 1
 
 **API Status:** Stable, changes only due to DOM being a moving target
 
-Version 1 of package dom is implemented on top of the [`github.com/gopherjs/gopherjs/js`](https://godoc.org/github.com/gopherjs/gopherjs/js) API and supports GopherJS only.
+Version 1 of package dom is implemented on top of the [`github.com/gopherjs/gopherjs/js`](https://pkg.go.dev/github.com/gopherjs/gopherjs/js) API and supports GopherJS only.
 
 ### Install
 
     go get honnef.co/go/js/dom
 
 ### Documentation
 
-For documentation, see https://godoc.org/honnef.co/go/js/dom.
+For documentation, see https://pkg.go.dev/honnef.co/go/js/dom.