docs(governance): committee for parameter governance

main/guides/governance/index.md

@@ -0,0 +1,33 @@
+# Contract Governance
+
+To help build systems with a good balance of decentralization and executive control, the Agoric platform includes, in addition to chain-wide governance included in the Cosmos SDK platform, an `@agoric/governance` package with a flexible archtecture supporting 3 main features:
+
+- Parameter Governance
+- API Governance
+- Offer Filters
+
+## Parameter Governance
+
+In [Starting a Contract Instance](../zoe/#starting-a-contract-instance), we saw that contracts are parameterized by _terms_. Parameter governance supports
+having an authorized party, the _electorate_, change such parameters while the contract is running.
+
+In [dapp-agoric-basics](https://github.com/Agoric/dapp-agoric-basics), the
+swaparoo contract has a governed `Fee` amount parameter:
+
+```js
+const paramTypes = harden(
+  /** @type {const} */ ({
+    Fee: ParamTypes.AMOUNT,
+  }),
+);
+```
+
+## The `committee.js` Electorate Contract
+
+This dapp uses the `committee.js` contract from `@agoric/governance` for its
+electorate. The core eval deployment script starts the swaparoo committee,
+gets invitations, and sends them to the the smart wallets of the voters.
+In `test-vote-by-committee.js`, the committee consists of just 1 voter:
+
+<img src="./assets/gov-param-1.svg"
+  style="border: 2px solid" width="600" />