Rework signer fees section for multiple lot sizes
Also reflect our final parametrization in number of signers per group,
and tweak the styling used for terminology to use a proper definition
list. And also drop capitalization for Signer and Deposit.
// Constants used throughout the spec. Generally (though not always) correspond
// to tBTC system constants.
+:signers: 3
+:threshold: 3
+
// Overcollateralization constants. Changes here should probably change some of
-// the content in bonding/index.adoc.
+// the content in bonding/index.adoc and signer-fees/index.adoc.
:extra-collateral: 50%
+:per-signer-collateral: 50%
:total-collateral: 150%
// Liquidation constants.
