Fixing minor incorrect and missing punctuation on the trading page. (#584)

Author: jckirton

docs/concepts/systems/trading.mdx

@@ -101,9 +101,9 @@ Trades can end in two ways: both parties accept the trade and the resources are
 
 ## Fees
 
-Use of the trade system incurs a fee, paid with ((%Fbits ⌽%)). The minimum trade fee is ((%F3⌽%))
+Use of the trade system incurs a fee, paid with ((%Fbits ⌽%)). The minimum trade fee is ((%F3⌽%)).
 
-The fee is based on the resources exchanged on completion of the trade - not all resources present,
+The fee is based on the resources exchanged on completion of the trade - not all resources present.
 
 The trade fee will be reduced if the involved parties are corp representatives or COMCODE supporters.