Prepare release 4.3.0 (#52)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d6c1483..ad7e43c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-# Unreleased
+# Release 4.3.0 (July 1, 2022)
 
 - Add `typing_extensions.NamedTuple`, allowing for generic `NamedTuple`s on
   Python <3.11 (backport from python/cpython#92027, by Serhiy Storchaka). Patch
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index e2b8d41..a58156b 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -35,7 +35,7 @@
 
 - Make sure your environment is up to date
 
- - `git checkout master`
+ - `git checkout main`
  - `git pull`
  - `python -m pip install --upgrade build twine`
 
diff --git a/pyproject.toml b/pyproject.toml
index 8c8f18c..6005d55 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,7 +6,7 @@
 # Project metadata
 [project]
 name = "typing_extensions"
-version = "4.2.0"
+version = "4.3.0"
 description = "Backported and Experimental Type Hints for Python 3.7+"
 readme = "README.md"
 requires-python = ">=3.7"