more migration to common docs (#370)

* more migration to common docs

* refactoring js

* removed duplicate docs

* migrating more docs

* more refactoring

* migrated browsers page

* updated summary

docs/blocks/logic/if.md

@@ -1,16 +1,6 @@
-# If
+# @extends
 
-### @parent blocks/language
- 
-
-Conditionally run code depending on whether a [Boolean](/blocks/logic/boolean) condition is true or false.
-
-```blocks
-if(true) {
-}
-```
-
-Click on the dark blue gear icon (see above) to add an *else* or *if* to the current block.
+## #examples
 
 ### Example: adjusting screen brightness
 
@@ -23,8 +13,3 @@ input.onButtonPressed(Button.A, () => {
     }
 })
 ```
-
-### See also
-
-[while loop](/blocks/loops/while), [for](/blocks/loops/for), [boolean](/blocks/logic/boolean)
-