doc: add min deposit amounts (#320)

* add min deposit amounts

* clarify min deposit amounts

* clarify again

* yet more clarification:

resources/testnet-releases.md

@@ -34,3 +34,15 @@ Core Version  | Start Height | End Height
 ------------- | ------------- | -------------
 v0.10.7 | 0 | 14700
 v0.13.0 | 14701 | N/A
+
+# Minimum transfer amounts
+
+For each asset X in (AXL, UST, LUNA) and each external chain Y in (Ethereum, non-Ethereum EVM, Cosmos/IBC): any transfer of asset X to chain Y must exceed the minimum amount given in the table below.  (If Y is the origin chain for asset X then this transfer is called "redeem"/"burn"; there is no minimum in this case.)
+
+If the total amount of asset X sent to a deposit address A is smaller than the minimum then those deposits will sit in the queue until a future deposit to A brings the total above the minimum.
+
+Asset symbol | Ethereum | non-Ethereum EVM | Cosmos/IBC
+---|---|---|---
+AXL | 100 AXL | 10 AXL | 0.1 AXL
+UST | 100 UST | 10 UST | 0.1 UST
+LUNA | 1 LUNA | 0.1 LUNA | 0.001 LUNA