Add token management to Settings

- Tracked Tokens well in settings with [x] remove buttons
- New settings-addtoken view with:
  - Top-10 quick-pick buttons (tracked ones dimmed+disabled)
  - Top-100 dropdown showing "Token Name (SYMBOL)", tracked disabled
  - Manual contract address entry with RPC lookup
- View comment in helpers.js about keeping README in sync

src/popup/index.js

@@ -20,6 +20,7 @@ const transactionDetail = require("./views/transactionDetail");
 const receive = require("./views/receive");
 const addToken = require("./views/addToken");
 const settings = require("./views/settings");
+const settingsAddToken = require("./views/settingsAddToken");
 const approval = require("./views/approval");
 
 function renderWalletList() {
@@ -60,6 +61,8 @@ const ctx = {
     showConfirmTx: (txInfo) => confirmTx.show(txInfo),
     showReceive: () => receive.show(),
     showTransactionDetail: (tx) => transactionDetail.show(tx),
+    showSettingsView: () => settings.show(),
+    showSettingsAddTokenView: () => settingsAddToken.show(),
 };
 
 // Views that can be fully re-rendered from persisted state.
@@ -70,6 +73,7 @@ const RESTORABLE_VIEWS = new Set([
     "address-token",
     "receive",
     "settings",
+    "settings-addtoken",
     "transaction",
     "success-tx",
     "error-tx",
@@ -120,6 +124,9 @@ function restoreView() {
         case "settings":
             settings.show();
             break;
+        case "settings-addtoken":
+            settingsAddToken.show();
+            break;
         case "transaction":
             if (state.viewData && state.viewData.tx) {
                 transactionDetail.render();
@@ -212,6 +219,7 @@ async function init() {
     receive.init(ctx);
     addToken.init(ctx);
     settings.init(ctx);
+    settingsAddToken.init(ctx);
 
     if (!state.hasWallet) {
         showView("welcome");