Merge PR #3954: Tx Broadcasting Sync by Default

docs/gaia/gaiacli.md

@@ -128,6 +128,19 @@ gaiacli keys show --multisig-threshold K name1 name2 name3 [...]
 For more information regarding how to generate, sign and broadcast transactions with a
 multi signature account see [Multisig Transactions](#multisig-transactions).
 
+### Tx Broadcasting
+
+When broadcasting transactions, `gaiacli` accepts a `--broadcast-mode` flag. This
+flag can have a value of `sync` (default), `async`, or `block`, where `sync` makes
+the client return a CheckTx response, `async` makes the client return immediately,
+and `block` makes the client wait for the tx to be committed (or timing out).
+
+It is important to note that the `block` mode should **not** be used in most
+circumstances. This is because broadcasting can timeout but the tx may still be
+included in a block. This can result in many undesirable situations. Therefor, it
+is best to use `sync` or `async` and query by tx hash to determine when the tx
+is included in a block.
+
 ### Fees & Gas
 
 Each transaction may either supply fees or gas prices, but not both.