Updating README.md to mention the possibility to set the version of FFmpeg

README.md

@@ -3,7 +3,7 @@
 Here is a script that downloads the source code of [FFmpeg](https://www.ffmpeg.org) library and assembles it for Android. The script produces shared libraries as well as header files. The output structure looks like this:  
 <img src="https://github.com/Javernaut/ffmpeg-android-maker/blob/master/images/output_structure.png" width="200">  
 The actual content of all this directories depends on how the FFmpeg was configured before assembling. For my purpose I enabled only *libavcodec*, *libavformat*, *libavutil* and *libswscale*, but you can set your own configuration to make the FFmpeg you need.
-The version of FFmpeg here is **4.1.4**. And the script expects to use **at least** Android NDK **r19** (*r20* also works ok). Starting with FFmpeg 4.1 and NDK r19 the whole process became much simpler.
+The version of FFmpeg here by default is **4.1.4** (but can be overridden). And the script expects to use **at least** Android NDK **r19** (*r20* also works ok). Starting with FFmpeg 4.1 and NDK r19 the whole process became much simpler.
 
 ## Supported architectures
 
@@ -24,4 +24,6 @@ And the actual Android app can be found [here](https://github.com/Javernaut/What
 
 ## Features
 
+**Setting your own FFmpeg version**. You can actually override the version of FFmpeg used by the script. See details [here](https://github.com/Javernaut/ffmpeg-android-maker/wiki/Invocation-parameters).
+
 **Text relocations monitoring**. After a build you can look into stats/text-relocations.txt file. That file lists all *.so files that were built and reports if they have text relocations. If you don't see any mentioning of 'TEXTREL' in the file, you are good. Otherwise, you will see exact binaries that have this problem.