Convert README to markdown.

README → README.md

-Changes to eSpeak to support building on a POSIX system by using autotools.
+# eSpeak Text-to-Speech
+
+This branch contains changes to eSpeak to support building on a POSIX system
+by using autotools.
 
 This does the following things:
-   1/  compile the libespeak library;
-   2/  compile the speak and espeak command-line applications;
-   3/  compile the espeakedit application;
-   4/  compile the voice data, creating an espeak-data directory.
+
+1.  compile the libespeak library;
+2.  compile the speak and espeak command-line applications;
+3.  compile the espeakedit application;
+4.  compile the voice data, creating an espeak-data directory.
 
 This branch also contains some bug fixes and improvements that get
 sent back upstream.
 
-
-BUILDING
-
+## Building
 
 The espeak and espeakedit programs, along with the espeak voices, can
 be built via the standard autotools commands:
 	$ make
 	$ sudo make install
 
-NOTE: The configure command detects various platform differences that
+__NOTE:__ The configure command detects various platform differences that
 the espeak makefiles don't cater for (e.g. different wxWidgets version)
 and detect the available audio setup to use automatically.
 
-
-HISTORICAL RELEASES
-
+## Historical Releases
 
 1.24.02 is the first version of eSpeak to appear in the subversion
 repository, but releases from 1.05 to 1.24 are available on the
 
 	$ git replace 8d59235f 63c1c019
 
-NOTE: The source releases contain the big_endian, espeak-edit, praat-mod,
+__NOTE:__ The source releases contain the big_endian, espeak-edit, praat-mod,
 riskos, windows_dll and windows_sapi folders. These do not appear in the
 source repository until later releases, so have been excluded from the
 historical commits to align them better with the 1.24.02 source commit.