chore: update changelog + update migration url

Author: jogly

CHANGELOG.md

@@ -1,11 +1,19 @@
 # Changelog
+
 All notable changes to this project will be documented in this file.  The
 format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
-This project tracks the **major** and **minor** versions set by
+This project tracks the **major** and **minor** versions set upstream by
 [`h3`](github.com/uber/h3), and introduces backwards-compatible updates and/or
 fixes via **patches** with patch version bumps.
 
+## 4.0.0
+
+All new functions to match H3 v4.
+
+See <https://h3geo.org/docs/library/migrating-3.x> for upstream changes, and the
+[README.md](./README.md) for upstream to h3-go binding name mapping.
+
 ## 3.7.1
 
 ### Added
@@ -44,9 +52,11 @@ fixes via **patches** with patch version bumps.
 ## 3.0.2
 
 ### Fixed
+
 * `go mod vendor` now works correctly (#30, #32)
 
 ### Added
+
 * Some useful H3 constants (#22):
   * `MaxResolution`
   * `NumIcosaFaces`

README.md

@@ -20,7 +20,7 @@ Check out [v3](https://github.com/uber/h3-go/tree/v3.7.1) or checkout the git ta
 
 **Migrating from v3?**
 
-Check out [v3 to v4 migration guide](https://h3geo.org/docs/next/library/migrating-3.x/).
+Check out [v3 to v4 migration guide](https://h3geo.org/docs/library/migrating-3.x).
 There have been no breaking changes to the format of H3 indexes.  Indexes
 generated by older versions can be parsed in v4, and vice-versa.
 
@@ -39,7 +39,7 @@ be built. Go should do the right thing when including this library:
 > implies the "cgo" build constraint, as though the file also said "// +build
 > cgo". Therefore, if cgo is disabled, files that import "C" will not be built by
 > the go tool. (For more about build constraints see
-> https://golang.org/pkg/go/build/#hdr-Build_Constraints).
+> <https://golang.org/pkg/go/build/#hdr-Build_Constraints>).
 
 If you see errors/warnings like _"build constraints exclude all Go files..."_,
 then the `cgo` build constraint is likely disabled; try setting `CGO_ENABLED=1`
@@ -57,21 +57,22 @@ go get github.com/uber/h3-go/v4
 import "github.com/uber/h3-go/v4"
 
 func ExampleLatLngToCell() {
-	latLng := h3.NewLatLng(37.775938728915946, -122.41795063018799)
-	resolution := 9 // between 0 (biggest cell) and 15 (smallest cell)
+ latLng := h3.NewLatLng(37.775938728915946, -122.41795063018799)
+ resolution := 9 // between 0 (biggest cell) and 15 (smallest cell)
 
-	cell := h3.LatLngToCell(latLng, resolution)
+ cell := h3.LatLngToCell(latLng, resolution)
 
-	fmt.Printf("%s", cell) 
-	// Output:
-	// 8928308280fffff
+ fmt.Printf("%s", cell)
+ // Output:
+ // 8928308280fffff
 }
 
 ```
 
-# C API 
+# C API
 
 ## Notes
+
 * `LatLng` returns `Lat` and `Lng` as degrees, instead of radians.
 * H3 C API function prefixes of `get` have been dropped in support of Golang's
  `Getter` [naming style](https://golang.org/doc/effective_go.html#Getters).
@@ -96,7 +97,7 @@ func ExampleLatLngToCell() {
 | `getHexagonAreaAvg`          | `HexagonAreaAvg* (3/3)`                            |
 | `cellArea`                   | `CellArea* (3/3)`                                  |
 | `getHexagonEdgeLengthAvg`    | `HexagonEdgeLengthAvg* (2/2)`                      |
-| `exactEdgeLength`            | `ExactEdgeLength* (3/3)`                           |
+| `exactEdgeLength`            | `EdgeLength* (3/3)`                                |
 | `getNumCells`                | `NumCells`                                         |
 | `getRes0Cells`               | `Res0Cells`                                        |
 | `getPentagons`               | `Pentagons`                                        |