Fixed typographical erros in the documentation

Used the RETF rules provided by Wikipedia to fix some typographical
errors in the Markdown files of the documentation with the following
script:

https://github.com/openstack/openstack-doc-tools/tree/master/cleanup/retf

Docker-DCO-1.1-Signed-off-by: Christian Berendt <berendt@b1-systems.de> (github: berendt)

Docker-DCO-1.1-Signed-off-by: Christian Berendt <berendt@b1-systems.de> (github: SvenDowideit)
blindly make all uses of e\.?g\.? into e.g.,

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Merge pull request #6764 from SvenDowideit/pr_out_blindly_make_all_uses_of_e_g_into_e_g_

blindly make all uses of e\.?g\.? into e.g.,