Add features excuse

Author: mloskot

README.md

@@ -3,17 +3,24 @@
 This extension provides support for [Boost.Jam](http://boost.org/build/)
 language in Visual Studio Code.
 
+![screenshot](images/screenshot.png)
+
 Boost.Jam is an interpreted language implemented by [Boost.Build](http://boost.org/build/)
 engine, `b2`, which loads the Jam code that implements the build system.
 Boost.Build is developed as part of [Boost](https://boost.org) project.
 
-![screenshot](images/screenshot.png)
-
 ## Features
 
 - Syntax highlighting
 - Code comments
 
+Although the process of writing a TextMate language grammar remains
+*poorly documented*, this is a *brave* first attempt to provide
+a minimal usable support for Boost.Jam. By no means, it is free from
+bugs or covers all elements of Boost.Jam language. Non-trivial TextMate
+grammars for Visual Studio Code count from 500 to 5000 lines of code,
+and this one *less than 200*.
+
 ## Acknowledgements
 
 - [Matt Neuburg](https://github.com/mattneub) for his [Writing a TextMate Grammar: Some Lessons Learned](http://www.apeth.com/nonblog/stories/textmatebundle.html).
@@ -28,7 +35,7 @@ This file contains language grammar for [Boost.Jam](http://boost.org/build/) syn
 The file was written from scratch and not converted from any existing TextMate grammar.
 
 If you want to provide a fix or improvement, awesome!
-Please improve the file adh create a pull request against this git repository.
+Please improve the file and create a pull request against this git repository.
 
 All contributions are welcome!