Various and sundry documentation formatting fixes.

core/lib/Drupal/Core/HtmlPageController.php

core/lib/Drupal/Core/Routing/ChainMatcher.php

core/lib/Drupal/Core/Routing/CompiledRoute.php

core/lib/Drupal/Core/Routing/FinalMatcherInterface.php

core/lib/Drupal/Core/Routing/FirstEntryFinalMatcher.php

core/lib/Drupal/Core/Routing/HttpMethodMatcher.php

core/lib/Drupal/Core/Routing/InitialMatcherInterface.php

core/lib/Drupal/Core/Routing/MatcherDumper.php

core/lib/Drupal/Core/Routing/NestedMatcher.php

core/lib/Drupal/Core/Routing/NestedMatcherInterface.php

core/lib/Drupal/Core/Routing/PartialMatcher.php

core/lib/Drupal/Core/Routing/PartialMatcherInterface.php

core/lib/Drupal/Core/Routing/RouteBuilder.php

core/lib/Drupal/Core/Routing/RouteCompiler.php