Make git-contacts more prominent in our docs.

Notable changes in v5
=====================

 * Drop mention of "/usr/share/..." as an "installed" path for
   "git-contacts"; instead point users to the script as a relative path
   inside the Git codebase
 * Minor wording tweaks to commit messages

Notable changes in v4
=====================

 * Avoid using "should" for guidance around using "git-contacts"
 * Clarify where to find the "git-contacts" script (because it's not a
   default builtin command)

Notable changes in v3
=====================

 * Refer to GitGitGadget via a link to MyFirstContribution (instead of
   sending readers to GGG's homepage directly)
 * Soften the advice for using git-contacts

Notable changes in v2
=====================

 * Improve existing mention of git-contacts in SubmittingPatches (instead of
   adding a separate, entirely new paragraph)
 * Add example usage of integrating git-contacts with git-send-email with
   the latter's --cc-cmd flag.
 * Various smaller fixes to SubmittingPatches

Linus Arver (8):
  MyFirstContribution: mention contrib/contacts/git-contacts
  SubmittingPatches: clarify 'git-contacts' location
  SubmittingPatches: mention GitGitGadget
  SubmittingPatches: quote commands
  SubmittingPatches: discuss reviewers first
  SubmittingPatches: dedupe discussion of security patches
  SubmittingPatches: add heading for format-patch and send-email
  SubmittingPatches: demonstrate using git-contacts with git-send-email

 Documentation/MyFirstContribution.txt | 10 ++++
 Documentation/SubmittingPatches       | 73 ++++++++++++++++-----------
 2 files changed, 53 insertions(+), 30 deletions(-)

base-commit: c2cbfbd2e28cbe27c194d62183b42f27a6a5bb87

Submitted-As: https://lore.kernel.org/git/pull.1704.v5.git.1713308518.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1704.git.1712017205754.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1704.v2.git.1712366536.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1704.v3.git.1712699815.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1704.v4.git.1712878339.gitgitgadget@gmail.com