[PATCH v5 0/3] Improve checks for valid_fqdn in send-email and update documentation

Hi all

This series of patches mainly has two changes:

1. Improve the checks for valid_fqdn in send-email to be more strict and
   compliant with RFC1035.
2. Update the documentation for send-email to include examples of using
   OAuth2.0 with Gmail and Outlook, as well as links to the credential
   helpers for these services.

P.S. I have used `git-credential-outlook` linked in the second and third patch for this email!

v2: - Improve grammar and add missing "" in second patch.
    - Separate footnotes and the trailer block with a blank line in the first
      patch.

v3: - Change link for email helpers since old one was too long.

v4: - Improve log message of first and second patch.
    - Update valid_fqdn check in first patch to allow one or more <upto 63
      octet run of alnum or hyphen that does not begin or end with hyphen>,
      separated by a single dot in between each.
    - Revert the documentation regarding sending patches to a mailing list
      in the second patch.

v5: - Simplify the regex in the first patch to check for valid FQDN.
    - Fix formatting in the second patch to make it more readable.

Aditya Garg (3):
  send-mail: improve checks for valid_fqdn
  docs: improve send-email documentation
  docs: add credential helper for outlook and gmail in OAuth list of
    helpers

 Documentation/git-send-email.adoc | 63 +++++++++++++++++++++++++++----
 Documentation/gitcredentials.adoc |  4 ++
 git-send-email.perl               |  4 +-
 3 files changed, 62 insertions(+), 9 deletions(-)