Minor Additions to Quick Start

#### Rational for "now install:"
I for one skipped install after glancing over the start of the original sentence, taking away that the paragraph was an alternate for deployed systems. Yes I overlooked the sub headline reading 'installing' and did not think. But it's the **quick** install guide.

#### Rational for Macports
Again, it's the quick install guide -- and it took me pretty long to figure what was not working and unearth the needed syntax for sudo, after finding the right path. In these fleeting times I almost gave up on giving LFE a whirl. It was compounded, I believe with an error in the Makefile, which runs `mkdir -p $(INSTALLDIR);$(BINDIR)` with the BINDIR being out of place in that line.


#### Commit message
*quick install markdown: added encouragement to ignore make warnings; added clarification that install is needed; added Macports install command line; corrected result of "ls -1 $ERL_LIBS|grep lfe": lfe;*