* Fix typos in openconnect.rst
change Cerbort->Certbot
Update first line to reflect that openconnect was introduced in 1.3-rolling (T2036)
* typo in dmvpn.rst
* ipsec.rst justification, minor phrasing changes
* l2tp.rst justification and phrasing changes.
* sstp.rst phrasing, justification changes
* Update ipsec.rst
rephrase for clarity and to avoid possessive plural apostrophe
The command to set the vpn interface is changed in the rolling release
which is not modified in many configuration examples, corrected syntax
in all pages where it is mentioned
There were minimal grammatical and spelling mistakes in the files which I
corrected as documentation proof reading.
Also added information about few ipsec vpn parameters.
