Replace TBTCv2 label with tBTC

Author: michalinacienciala

docs/SUMMARY.md

@@ -83,7 +83,7 @@
   * [Random Beacon API](app-development/staking-contract-and-dao/staking-contract-and-dao-api/generated-docs/index.md)
 * [Random Beacon](app-development/random-beacon/README.md)
   * [Random Beacon API](app-development/random-beacon/random-beacon-api/generated-docs/index.md)
-* [TBTCv2](app-development/tbtc-v2/README.md)
+* [tBTC](app-development/tbtc-v2/README.md)
   * [ECDSA API](app-development/tbtc-v2/ecdsa-api/generated-docs/index.md)
   * [Bridge API](app-development/tbtc-v2/tbtc-v2-api/generated-docs/index.md)
 

docs/app-development/tbtc-v2/README.md

@@ -1,4 +1,4 @@
-# TBTCv2
+# tBTC
 
 To get familiarized with ECDSA contracts API, go [here](ecdsa-api/generated-docs/index.md).