add notes on verbosity levels for viewing logs in stdout (#851)

Author: dmfxyz

cli/src/opts/evm.rs

@@ -71,6 +71,7 @@ pub struct EvmArgs {
 
     #[clap(
         help = r#"Verbosity mode of EVM output as number of occurences of the `v` flag (-v, -vv, -vvv, etc.)
+    2: print test logs for all tests
     3: print test trace for failing tests
     4: always print test trace, print setup for failing tests
     5: always print test trace and setup

forge/README.md

@@ -305,6 +305,16 @@ console.log(someValue);
 
 ```
 
+Note: to make logs visible in `stdout`, you must use at least level 2 verbosity.
+```bash
+$> forge test -vv
+[PASS] test1() (gas: 7683)
+...
+Logs:
+  <your log string or event>
+  ...
+```
+
 ## Remappings
 If you are working in a repo with NPM-style imports, like
 ```