Update extensions-defold-sdk.md

docs/en/manuals/extensions-defold-sdk.md

@@ -13,7 +13,7 @@ You use the Defold SDK by including the `dmsdk/sdk.h` header file:
 
     #include <dmsdk/sdk.h>
 
-The header file is not publicly published but all of the available SDK functions are documented in our [API reference](/ref/dmExtension/). The SDK contains the following namespaces with functions:
+The available SDK functions are documented in our [API reference](/ref/dmExtension/). The SDK contains the following namespaces with functions:
 
 * [Align](/ref/dmAlign/) - Alignment macros. Use for compiler compatibility
 * [Array](/ref/dmArray/) - Templatized array with bounds checking.
@@ -44,3 +44,5 @@ The header file is not publicly published but all of the available SDK functions
 * [Web Server](/ref/dmWebServer/) - API for a simple high-level single-threaded Web server based on dmHttpServer.
 * [Shared Library](/ref/sharedlibrary/) - Utility functions for shared library export/import.
 * [Sony vector Math Library](../assets/Vector_Math_Library-Overview.pdf) - The Sony Vector Math library mainly provides functions used in 3-D graphics for 3-D and 4-D vector operations, matrix operations, and quaternion operations.
+
+If you need the `dmsdk/sdk.h` header file for code completion in your editor of choice it can be found [here in the main GitHub repository for Defold](https://github.com/defold/defold/blob/dev/engine/sdk/src/dmsdk/sdk.h) with [header files for the individual namespaces here](https://github.com/defold/defold/tree/dev/engine/dlib/src/dmsdk/dlib).