Update meaning of base fee on docs

[sreuland]

What version are you using?

master

What did you do?

Read the docs on transaction base fee here

What did you expect to see?

description of a transaction base fee here states that the fee represents the total maximum fee allowable for the transaction as a whole including all operations.

What did you see instead?

The description of a transaction base fee here, states that the transaction fee represents the per-operation max fee, and the fee would be multiplied per operation to arrive at total tx fee which is mis-leading, as it really represents the final total fee allowable for the tx, not per-operation.