Have makefile print out list of targets

[ctb]

a la

 https://github.com/swcarpentry/lesson-template/blob/gh-pages/Makefile           

@gvwilson quoth:

The trick is to use '##' to mark comments you want printed, then have           
'all' run                                                                       

@sed -n 's/^##//p' $<                                                           

to find and print those lines.  It's not automatic - comments can get out       
of step - but it works well enough.                                             

[gvwilson]

On 2015-02-15 10:46 AM, C. Titus Brown wrote:

@gvwilson https://github.com/gvwilson quoth:
Actually, I "sayeth" - you "quoth".

[ctb]

https://www.google.com/search?q=quoth&oq=quoth

[mr-c]

+1

[standage]

I got this.