Update FAQ instructions for MacOS

[greyvugrin]

Providing the --with options is deprecated and caused confusion when trying to set things up for the first time. Updated instructions with up to date defaults.

Addresses comments like #573

[npetzall]

@rafalkasa I want to be lazy, should we move the FAQ to a wiki page on GitHub instead and just link to it from ReadTheDocs.
Would avoid some of the versioning problems that exist.

Also we have the same type of FAQ both in read the docs and also in readme.md.

schemaspy/README.md

Lines 77 to 87 in 1aa5f09

	#### Graphviz
	There have been lots of issue with graphviz and OSX
	So install using brew `brew install graphviz --with-librsvg --with-pango`
	If you already have graphviz installed you need to uninstall and then install
	```
	brew uninstall graphviz
	brew install graphviz --with-pango --with-librsvg
	```
	Depending on OSX version
	*Older than High Sierra*, add `-renderer :quartz` to the commandline
	*High Sierra or newer*, add `-renderer :cairo` to the commandline

Both could be links to a wikipage, that I guess we could allow others to update, just like a normal wikipage.

[rafalkasa]

@npetzall sounds good for me :-)

[npetzall]

@rafalkasa I see that wiki can only be edited by user with push access. This can be disabled and anyone can update the wiki. Should we put our trust in the github community....

Other options are FAQ.md and have pushes for that specific file that isn't "version" specific.