Update 'config/distribution/policies.json'

⛔️ Disabled StartPage, Twitter and Yahoo extensions (like search engines)
⛔️ Disabled Bing, Google, Twitter, Amazon and eBay as preinstalled search engines in ESR versions
ℹ️ Removed custom folder with some usefull about: pages
ℹ️ Removed StartPage as default search engine in ESR versions

config/distribution/policies.json

@@ -1,51 +1,6 @@
 {
 	"policies": {
 
-    "Bookmarks": [
-      {
-        "Title": "RESTART",
-        "URL": "about:restartrequired",
-        "Placement": "menu",
-        "Folder": "ADVANCED"
-      },
-      {
-        "Title": "about:config",
-        "URL": "about:config",
-        "Placement": "menu",
-        "Folder": "ADVANCED"
-      },
-      {
-        "Title": "ALL about:",
-        "URL": "about:about",
-        "Placement": "menu",
-        "Folder": "ADVANCED"
-      },
-      {
-        "Title": "POLICIES",
-        "URL": "about:policies",
-        "Placement": "menu",
-        "Folder": "ADVANCED"
-      },
-      {
-        "Title": "NETWORKING",
-        "URL": "about:networking",
-        "Placement": "menu",
-        "Folder": "ADVANCED"
-      },
-      {
-        "Title": "PROFILES",
-        "URL": "about:profiles",
-        "Placement": "menu",
-        "Folder": "ADVANCED"
-      },
-      {
-        "Title": "SUPPORT",
-        "URL": "about:support",
-        "Placement": "menu",
-        "Folder": "ADVANCED"
-      }
-    ],
-
     "CaptivePortal": false,
 
     "Certificates": {
@@ -97,6 +52,10 @@
       "Fingerprinting": false
     },
 
+    "Extensions": {
+      "Uninstall": ["startpage@search.mozilla.org", "twitter@search.mozilla.org", "yahoo@search.mozilla.org"]
+    },
+
     "ExtensionUpdate": true,
 
     "FlashPlugin": {
@@ -117,10 +76,7 @@
 
     "Homepage": {
       "URL": "about:blank",
-      "Locked": true,
-      "Additional": ["http://example.org/",
-                     "http://example.edu/"],
-      "StartPage": "none"
+      "Locked": true
     },
 
     "NewTabPage": false,
@@ -174,19 +130,8 @@
     },
 
     "SearchEngines": {
-	    	"Default": "StartPage",
 	    	"PreventInstalls": false,
-	    	"Remove": ["Bing", "Google", "Twitter", "Amazon.com", "eBay"],
-            "Add": [
-              {
-                "Name": "StartPage",
-                "Alias": "",
-                "Description": "The world's most private search engine",
-                "URLTemplate": "https://www.startpage.com/do/search?query={searchTerms}",
-                "IconURL": "https://www.startpage.com/assets/images/logo-180x180.png",
-                "Method": "GET"
-              }
-            ]
+	    	"Remove": ["Bing", "Google", "Twitter", "Amazon.com", "eBay"]
     },
 
     "SearchSuggestEnabled": false,