Update version files for 2.0.0

Update documentation and version tags for final 2.0.0 release.

Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/docs/release-notes.md b/docs/release-notes.md
index 2fc96f7..45b32e6 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -64,6 +64,7 @@
   partitions.
 - Serial recovery with MBEDTLS no longer has undefined operations which
   led to usage faults when the secondary slot image was encrypted.
+- espressif: allow the use of a different toolchain for building
 
 ## Version 1.10.0