Use Bootstrap dark theme in dark mode (#428)

Author: zbynek

src/main/java/io/jenkins/plugins/darktheme/DarkThemeManagerFactory.java

@@ -14,6 +14,7 @@ public class DarkThemeManagerFactory extends ThemeManagerFactory {
     public static final String THEME_URL_NAME = "theme-dark";
     public static final String ACE_EDITOR_THEME = "tomorrow_night";
     public static final String PRISM_THEME = "tomorrow";
+    public static final String BOOTSTRAP_THEME = "dark";
 
     @DataBoundConstructor
     public DarkThemeManagerFactory() {
@@ -25,6 +26,7 @@ public Theme getTheme() {
                 .withCssUrl(getCssUrl())
                 .withProperty("ace-editor", "theme", ACE_EDITOR_THEME)
                 .withProperty("prism-api", "theme", PRISM_THEME)
+                .withProperty("bootstrap", "theme", BOOTSTRAP_THEME)
                 .build();
     }
 

src/main/java/io/jenkins/plugins/darktheme/DarkThemeSystemManagerFactory.java

@@ -22,6 +22,7 @@ public Theme getTheme() {
             .respectSystemAppearance()
             .withProperty("ace-editor", "theme-dark", ACE_EDITOR_THEME)
             .withProperty("prism-api", "theme-dark", PRISM_THEME)
+            .withProperty("bootstrap", "theme-dark", BOOTSTRAP_THEME)
             .build();
     }