ci(release): update readme (#21)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

README.md

@@ -14,13 +14,14 @@ The programs, version numbers, and the date stamp on the downloaded file used to
 | ------- | ------- | ---- |
 | crt | 1.3.1 | 04/11/2017 |
 | gridgen | 1.0.02 | 10/24/2018 |
-| libmf6 | 6.4.1 | 12/09/2022 |
+| libmf6 | 6.4.2 | 06/29/2023 |
 | mf2000 | 1.19.01 | 03/30/2010 |
 | mf2005 | 1.12.00 | 12/07/2021 |
-| mf6 | 6.4.1 | 12/09/2022 |
+| mf6 | 6.4.2 | 06/29/2023 |
 | mflgr | 2.0.0 | 09/20/2013 |
 | mfnwt | 1.3.0 | 09/07/2022 |
 | mfusg | 1.5 | 02/27/2019 |
+| mfusg_gsi | 2.1.1 | None |
 | mp6 | 6.0.1 | 10/23/2018 |
 | mp7 | 7.2.001 | 10/23/2018 |
 | mt3dms | 5.3.0 | 02/21/2010 |
@@ -29,6 +30,6 @@ The programs, version numbers, and the date stamp on the downloaded file used to
 | swtv4 | 4.00.05 | 10/24/2018 |
 | triangle | 1.6 | 07/29/2005 |
 | vs2dt | 3.3 | 04/02/2018 |
-| zbud6 | 6.4.1 | 12/09/2022 |
+| zbud6 | 6.4.2 | 06/29/2023 |
 | zonbud3 | 3.01 | 10/25/2018 |
 | zonbudusg | 1.5 | 02/27/2019 |