doc: mention $PATH

Signed-off-by: Merlin Ran <merlinran@gmail.com>

README.md

@@ -27,11 +27,12 @@ make install
 ```
 
 ## Getting Started
-1. `bidbot init`
+1. Make sure `$GOPATH/bin` is in your `$PATH`, i.e., `export PATH=$GOPATH/bin:$PATH`.
+1. `bidbot init`.
 1. The output will ask you to sign a token with the owner address of your miner.
 1. Configure your _ask price_, other bid settings, and auction filters. See `bidbot help daemon` for details. You can edit the configuration file generated by `bidbot init` or use the equivalent flag for any given option.
 1. Use the signature you generated above to start the daemon: `bidbot daemon --miner-addr [address] --wallet-addr-sig [signature]`
-1. Good luck! Your `bidbot` will automatically bid in open deal auctions. If it wins an auction, the broker will automatically start making a deal with the Lotus wallet address used in step 1.
+1. Good luck! Your `bidbot` will automatically bid in open deal auctions. If it wins an auction, the broker will automatically start making a deal with the Lotus wallet address used in step 3.
 
 ## Contributing