Update join-mainnet.md (cosmos#728)

docs/gaia-tutorials/join-mainnet.md

@@ -10,15 +10,18 @@ order: 3
 **Instant Gratification Snippet**
 
 ```bash
-git clone -b v4.0.4 https://github.com/cosmos/gaia
+git clone -b v4.0.5 https://github.com/cosmos/gaia
+cd gaia
 make install
 gaiad init chooseanicehandle
 wget https://github.com/cosmos/mainnet/raw/master/genesis.cosmoshub-4.json.gz
 gzip -d genesis.cosmoshub-4.json.gz
 mv genesis.cosmoshub-4.json ~/.gaia/config/genesis.json
-gaiad start --p2p.seeds bf8328b66dceb4987e5cd94430af66045e59899f@public-seed.cosmos.vitwit.com:26656,[email protected]:26656,[email protected]:26656,ba3bacc714817218562f743178228f23678b2873@public-seed-node.cosmoshub.certus.one:26656,[email protected]:26656
+gaiad start --p2p.seeds bf8328b66dceb4987e5cd94430af66045e59899f@public-seed.cosmos.vitwit.com:26656,[email protected]:26656,[email protected]:26656,ba3bacc714817218562f743178228f23678b2873@public-seed-node.cosmoshub.certus.one:26656,[email protected]:26656 --x-crisis-skip-assert-invariants
 ```
 
+Note:  If your node is unable to connect to any of the seeds listed here, you can find seeds and peers in [this document](https://hackmd.io/@KFEZk8oMTz6vBlwADz0M4A/BkKEUOsZu#).
+
 If you'd like to save those seeds to your settings put them in ~/.gaia/config/config.toml in the p2p section under seeds in the same comma-separated list format.
 
 **You need to [install gaia](./installation.md) before you go further**