Updated the README.md documentation to be more explicit.

The location of the library was not specified explicity. It has now
been updated so that it's more clear that an example of the path
on RISC OS is !Boot.Library.

README.md

@@ -25,12 +25,13 @@ to a location where they can be executed from, such as `/usr/local/bin` or `~/bi
 
 ## Installation on RISC OS systems
 
-The RISC OS archive contains a set of tools to place somewhere that they can be executed,
-such as within your library. A common installation would be to copy all the files and
-directories from `Tools.XML` to your library.
+The RISC OS archive contains a set of tools to place somewhere that they can be
+executed, such as within your library. A common installation would be to copy all
+the files and directories from `Tools.XML` into your library, eg `!Boot.Library`.
 
 The distribution for RISC OS includes the `perl`, `xsltproc` and `xmllint` binaries.
-The version of perl supplied is suitable for use with the tool only.
+The version of perl supplied is suitable for use with the tool only. These must be
+available on the path.
 
 
 ## Requirements