add office 2021 keys

README.md

@@ -120,6 +120,23 @@ Authoritative source on Microsoft's [TechNet](https://technet.microsoft.com/en-u
 | Windows Server 2008 R2 Datacenter                 | 74YFP-3QFB3-KQT8W-PMXWJ-7M648 |
 | Windows Server 2008 R2 for Itanium-based Systems  | GT63C-RJFQ3-4GMB6-BRFB9-CB83V |
 
+### Office LTSC 2021
+| Product                            | GVLK                          |
+| ---------------------------------- | ----------------------------- |
+| Office LTSC Professional Plus 2021 | FXYTK-NJJ8C-GB6DW-3DYQT-6F7TH |
+| Office LTSC Standard 2021          | KDX7X-BNVR8-TXXGX-4Q7Y8-78VT3 |
+| Project Professional 2021          | FTNWT-C6WBT-8HMGF-K9PRX-QV9H8 |
+| Project Standard 2021              | J2JDC-NJCYY-9RGQ4-YXWMH-T3D4T |
+| Visio LTSC Professional 2021       | KNH8D-FGHT4-T8RK3-CTDYJ-K2HT4 |
+| Visio LTSC Standard 2021           | MJVNY-BYWPY-CWV6J-2RKRT-4M8QG |
+| Access LTSC 2021                   | WM8YG-YNGDD-4JHDC-PG3F4-FC4T4 |
+| Excel LTSC 2021                    | NWG3X-87C9K-TC7YY-BC2G7-G6RVC |
+| Outlook LTSC 2021                  | C9FM6-3N72F-HFJXB-TM3V9-T86R9 |
+| PowerPoint LTSC 2021               | TY7XF-NFRBR-KJ44C-G83KF-GX27K |
+| Publisher LTSC 2021                | 2MW9D-N4BXM-9VBPG-Q7W6M-KFBGQ |
+| Skype for Business LTSC 2021       | HWCXN-K3WBT-WJBKY-R8BD9-XK29P |
+| Word LTSC 2021                     | TN8H9-M34D3-Y64V9-TR72V-X79KV |
+
 ### Office 2019
 | Product                       | GVLK                          |
 | ----------------------------- | ----------------------------- |