Add solidity content (#1867)

* Update 100-solidity.md

* Update content/roadmaps/112-blockchain/content/103-smart-contracts/100-programming-languages/100-solidity.md

Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

content/roadmaps/112-blockchain/content/103-smart-contracts/100-programming-languages/100-solidity.md

@@ -10,4 +10,6 @@ Like any other programming languages, Solidity also has variables, functions, cl
 <ResourceGroupTitle>Free Content</ResourceGroupTitle>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://soliditylang.org/'>Solidity Programming Language</BadgeLink>
 <BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.tutorialspoint.com/solidity/index.htm'>Solidity Tutorial</BadgeLink>
-<BadgeLink badgeText='Watch' href='https://youtu.be/gyMwXuJrbJQ'>Learn Blockchain, Solidity, and Full Stack Web3 Development</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Watch' href='https://www.youtube.com/watch?v=ipwxYa-F1uY'>Solidity Course by FreeCodeCamp</BadgeLink>
+<BadgeLink colorScheme='blue' badgeText='Watch' href='https://www.youtube.com/watch?v=EhPeHeoKF88'>Solidity Course by Dapp University</BadgeLink>
+<BadgeLink badgeText='Watch' href='https://youtu.be/gyMwXuJrbJQ'>Learn Blockchain, Solidity, and Full Stack Web3 Development</BadgeLink>