feat: Moves vendor branch views to their own files, starts to implement snapshot testing for html

Tests/HtmlSnapshotTestingTests/HtmlSnapshotTestingTests.swift

@@ -0,0 +1,12 @@
+@testable import App
+import Elementary
+import HtmlSnapshotTesting
+import SnapshotTesting
+import XCTest
+
+final class SnapshotTestingTests: XCTestCase {
+  func testSimple() {
+    let doc = MainPage.loggedIn(next: nil)
+    assertSnapshot(of: doc, as: .html)
+  }
+}