Update README.md

Included bounties 20 & 21.

bounties-overview/README.md

@@ -22,6 +22,9 @@
 | 17 | Discord Video Bot | #151   | 20.04.21 | $100   | [362](https://testnet.joystream.org/#/forum/threads/362) | Completed   | NA  | NA                         |
 | 18 | Original Video Bounty | #162   | 29.05.21 | up to $200  | [422](https://testnet.joystream.org/#/forum/threads/422) | Open   | NA  | NA                         |
 | 19 | Validator Logging Tool | #161   | 20.04.21 | $400   | [381](https://testnet.joystream.org/#/forum/threads/381) | Announced          | NA  | NA                         |
+|20|Github Bounty Guide| #220| 04.07.21| $350|[492](https://testnet.joystream.org/#/forum/threads/492)|Announced| NA |NA|
+|21| Website Translation|#212|28.06.21|$500|[493](https://testnet.joystream.org/#/forum/threads/493)|Announced|NA|NA|
+
 
 
 ## Bounties Management