Create a new README and some minor info updates

README.md

@@ -0,0 +1,60 @@
+# PHP GnuPG
+
+The php-gnupg is a wrapper for GpgME library that provides access to GnuPG.
+
+
+## Installation
+
+### Linux
+
+Before starting with installation of this extensions, the `GpgME` library has to be installed. It
+has got installation packages on the most Linux distributions. The minimal version of GpgME that
+is supported is 1.3.0. The extension supports GnuPG version 1 and 2.
+
+Of course PHP has to be installed too. The minimal version that is supported is 5.3.2.
+
+#### PECL
+
+This extension is available on PECL. 
+
+```
+$ sudo pecl install gnupg
+```
+
+#### Manual Installation
+
+It's important to have a git installed as it's necessary for recursive fetch of
+[phpc](https://github.com/bukka/phpc).
+
+First clone recursively the repository
+```
+git clone --recursive https://github.com/php-gnupg/php-gnupg.git
+```
+
+Then go to the created directory and compile the extension. The PHP development package has to be
+installed (command `phpize` must be available).
+```
+cd php-gnupg
+phpize
+./configure
+make
+sudo make install
+```
+
+Finally the following line needs to be added to `php.ini`
+```
+extension=gnupg.so
+```
+or for PHP 8+ it's just
+```
+extension=gnupg
+```
+
+### Windows
+
+The extension is not currently supported on Windows due to unavailable GpgME library builds that
+would be supported by PHP.
+
+## Documentation
+
+The extension documentation is now available in the PHP-Manual: http://php.net/manual/en/book.gnupg.php