Change default `HISTFILE` path from `~/.zhistory` to more conventional
`~/.zsh_history`. This aligns better with Debian variants, macOS and
Oh My Zsh.
This would provide an easier onboarding experience to users coming to
Prezto from standard (framework free) zsh or from Oh My Zsh.
For existing Prezto users, we attempt to automatically rename old
`HISTFILE` to new one iff the old one exists and the new one doesn't.
However, if both old and new `HISTFILE` exist and the old one is more
recent, we just alert the user about what changed with a suggested way
to accommodate the change.
- Add missing documentation for options and environment variables
- Rearrange definition and documentation of 'Options', 'Variables'
and 'Aliases' in a consistent order
The 'history' command is the same as 'fc -l', using a '.' as the first
parameter will get the history from the first command starting with a '.'.
Instead a '0' should be used, meaning that the history is taken from the very
first entry in the history.
