Updated description.

README.md

@@ -3,57 +3,92 @@
 Version 0.7.4, 23 March 2010
 
 ## Description
+
 This package is used to extract the revision and file information provided
-by the subversion revision control system.
+by the [Subversion](http://subversion.apache.org/) revision control system.
+
+To maintain different versions of a document or to keep track on the development of one,
+the document is kept under a revision control system like SCCS, CVS, or Subversion.
+This LaTeX package assumes you are using the Subversion system. To present the version
+information of a document, one needs to extract it from some kind of text inserted by
+the revision control system. Subversion offers therefore the `Id` keyword, which is
+expanded by the Subversion update command and contains a lot of useful information.
+This information is made available through this package. The information obtained
+from the expanded string are:
+
+* The filename,
+* the revision number,
+* the date and time of the last Subversion co command, and
+* name of the user who has done this action.
+
+For each of these items a macro is defined. When updating a file, the Subversion
+keywords should be contained in the updated source. Further, one has to set the
+Subversion property for keyword expansion of that file, e.g.
+
+```LaTeX
+svn propset svn:keywords "Id" svninfo.dtx
+```
 
 ## Installation
+
 To install: unpack and
-```
+
+```shell
     make
 ```
+
 or execute the commands manually:
-```
+
+```shell
     latex svninfo.ins     // creates the file of this package
     latex svninfo.dtx     // create the package documentation
 ```
 
 The following files are created by 'latex svninfo.ins'
-```
-	svninfo.cfg
-	svninfo.sty
-	svninfo.perl
-	svninfo.init
+
+```shell
+ svninfo.cfg
+ svninfo.sty
+ svninfo.perl
+ svninfo.init
 ```
 
 then copy the files
-```
+
+```shell
     svninfo.sty
     svninfo.cfg
 ```
+
 to a place where LaTeX can find it, e.g.,
-```
+
+```shell
     $HOME/tex/inputs
 ```
+
 and set the environment variable
-```
+
+```shell
     TEXINPUTS=$HOME/tex/inputs//:$TEXINPUTS
 ```
 
 ## License
 
 This program can be redistributed and/or modified under the terms of the LaTeX
-Project Public License Distributed from CTAN archives in directory 
+Project Public License Distributed from CTAN archives in directory
 macros/latex/base/lppl.txt; either version 1.3c of the License, or (at your
 opinion) any later version.
 
 You are allowed to distribute this file under the condition that it is
 distributed together with all the following files:
-```
+
+```shell
    svninfo.ins
    svninfo.dtx
    Makefile
    README
 ```
+
 If you receive only some of these files from someone, complain!
 
 SPDX-License-Identifier: LPPL-1.3c+