[TYPO3-core] RFC #9745: Add INSTALL.txt to TYPO3 source package

[Christopher Stelmaszyk]

A further idea:

The parts "installation (not recommended)" and "installation recommended" 
are OK, but in these parts you get the information that there are the tar.gz 
and the zip package of source and dummy you could download.
This information should already be given in the part "Obtaining TYPO3", 
because you have to decide which one to use when downloading the packages.

Christopher