Clarify crash event logging and crash check prerequisite conditions in documentation

Sub: common-autopilots.rst: mention commercially used options

update LAND mode wiki landing-detection vertical speed threshold

Fix formatting of LAND_REPOSITION references in docs

Add info on LAND_REPOSITION param

Sub: sub-frames.rst: move to table, add context

Sub: introduction: update from original docs

common: update vimdrones logo image

Dev: update release procedures page

Copter: AutoTrim - Add an image and correct a description to reflect new MP version

dev: mavlink-commands.rst: link to protocol docs

dev: mavlink-get-set-params.rst: add Sub html

Copter: Add doc on newly supported auto_trim in position hold modes and fix punctuation

Dev: security page gets link to remote id

Common: remoteid page copied to dev wiki