make "make quick" quick by adding hints about the used section variables

This patch was created using

  find -name *.v | xargs -L 1 awk -i inplace '{from = 0} /^From/{ from = 1; ever_from = 1} { if (from == 0 && seen == 0 && ever_from == 1) { print "Set Default Proof Using \"Type*\"."; seen = 1 } }1 '

and some minor manual editing
2 jobs for master in 10 minutes and 49 seconds
Status Job ID Name Coverage
  Test
passed #2215
coq
iris-coq8.5.3

00:06:03

passed #2216
coq
iris-coq8.6

00:04:46