Update flags-configs.mdx

Small adjustments removing devnet mention

docs/berkeley-upgrade/flags-configs.mdx

@@ -33,7 +33,7 @@ https://github.com/MinaProtocol/mina/releases/tag/3.0.0devnet
 
 ### Block Producer​s
 
-Start your node in the Devnet with the flags and environment variables listed below.
+Start your node post-upgrade in Mainnet with the flags and environment variables listed below.
 
 ```
 mina daemon
@@ -52,7 +52,7 @@ MINA_PRIVKEY_PASS
 ```
 
 ### SNARK Coordinator
-Configure your node in the Devnet with specific flags and environment variables as listed.
+Configure your node post-upgrade in Mainnet with specific flags and environment variables as listed.
 
 ```
 mina daemon
@@ -71,7 +71,7 @@ MINA_LIBP2P_PASS
 ```
 
 ### SNARK Workers
-Connect to SNARK Coordinator node if required and run the following flags.
+Connect to a SNARK Coordinator node if required and run the following flags.
 ```
 mina internal snark-worker
 --proof-level full