docs: update README for release v0.26.0

Signed-off-by: Sven Anderson <sven@redhat.com>

Author: ansiwen

README.md

@@ -73,6 +73,7 @@ go test -tags pacific ....
 
 | go-ceph version | Supported Ceph Versions | Deprecated Ceph Versions |
 | --------------- | ------------------------| -------------------------|
+| v0.26.0         | pacific, quincy, reef   | nautilus, octopus        |
 | v0.25.0         | pacific, quincy, reef   | nautilus, octopus        |
 | v0.24.0         | pacific, quincy, reef   | nautilus, octopus        |
 | v0.23.0         | pacific, quincy, reef   | nautilus, octopus        |