Move /plugin/name/ to /plugins/name/

The web files for plugins were hosted at /plugin/plugin_name/ while the
view page for a plugin is hosted at /plugins/plugin_name/view.  Reduce
confusion by making both urls use the plural version.

packages/master/master.js

@@ -2049,7 +2049,7 @@ async function startServer(args) {
 
 		let pluginPackagePath = require.resolve(path.posix.join(pluginInfo.requirePath, "package.json"));
 		let webPath = path.join(path.dirname(pluginPackagePath), "dist", "web");
-		app.use(`/plugin/${pluginInfo.name}`, express.static(webPath));
+		app.use(`/plugins/${pluginInfo.name}`, express.static(webPath));
 	}
 
 	// Load plugins

packages/web_ui/src/bootstrap.jsx

@@ -42,7 +42,7 @@ async function loadPlugins() {
 	await __webpack_init_sharing__("default");
 	for (let meta of pluginList) {
 		try {
-			await loadScript(`${basename}/plugin/${meta.name}/remoteEntry.js`);
+			await loadScript(`${basename}/plugins/${meta.name}/remoteEntry.js`);
 			let container = window[`plugin_${meta.name}`];
 			if (!container) {
 				throw new Error(`Plugin did not expose its container via plugin_${meta.name}`);

plugins/global_chat/webpack.config.js

@@ -9,7 +9,7 @@ module.exports = (env = {}) => merge(common(env), {
 	context: __dirname,
 	entry: "./web/index.jsx",
 	output: {
-		publicPath: "/plugin/global_chat/",
+		publicPath: "/plugins/global_chat/",
 		filename: "bundle.js",
 		path: path.resolve(__dirname, "dist", "web"),
 	},

plugins/research_sync/webpack.config.js

@@ -9,7 +9,7 @@ module.exports = (env = {}) => merge(common(env), {
 	context: __dirname,
 	entry: "./web/index.jsx",
 	output: {
-		publicPath: "/plugin/research_sync/",
+		publicPath: "/plugins/research_sync/",
 		filename: "bundle.js",
 		path: path.resolve(__dirname, "dist", "web"),
 	},

plugins/statistics_exporter/webpack.config.js

@@ -9,7 +9,7 @@ module.exports = (env = {}) => merge(common(env), {
 	context: __dirname,
 	entry: "./web/index.jsx",
 	output: {
-		publicPath: "/plugin/statistics_exporter/",
+		publicPath: "/plugins/statistics_exporter/",
 		filename: "bundle.js",
 		path: path.resolve(__dirname, "dist", "web"),
 	},

plugins/subspace_storage/webpack.config.js

@@ -9,7 +9,7 @@ module.exports = (env = {}) => merge(common(env), {
 	context: __dirname,
 	entry: "./web/index.jsx",
 	output: {
-		publicPath: "/plugin/subspace_storage/",
+		publicPath: "/plugins/subspace_storage/",
 		filename: "bundle.js",
 		path: path.resolve(__dirname, "dist", "web"),
 	},