How to: database location
in-volume (`.hist/up2k.db`, default) or somewhere else

copyparty creates a subfolder named `.hist` inside each volume where it stores the database, thumbnails, and some other stuff

this can instead be kept in a single place using the `--hist` argument, or the `hist=` volflag, or a mix of both:
* `--hist ~/.cache/copyparty -v ~/music::r:c,hist=-` sets `~/.cache/copyparty` as the default place to put volume info, but `~/music` gets the regular `.hist` subfolder (`-` restores default behavior)

by default, the per-volume `up2k.db` sqlite3-database for `-e2d` and `-e2t` is stored next to the thumbnails according to the `--hist` option, but the global-option `--dbpath` and/or volflag `dbpath` can be used to put the database somewhere else

if your storage backend is unreliable (NFS or bad HDDs), you can specify one or more "landmarks" to look for before doing anything database-related. A landmark is a file which is always expected to exist inside the volume. This avoids spurious filesystem rescans in the event of an outage. One line per landmark (see example below)

note:
* putting the hist-folders on an SSD is strongly recommended for performance
* markdown edits are always stored in a local `.hist` subdirectory
* on windows the volflag path is cyglike, so `/c/temp` means `C:\temp` but use regular paths for `--hist`
  * you can use cygpaths for volumes too, `-v C:\Users::r` and `-v /c/users::r` both work

config file example:

```yaml
[global]
  hist: ~/.cache/copyparty  # put db/thumbs/etc. here by default

[/pics]
  /mnt/nas/pics
  flags:
    hist: -  # restore the default (/mnt/nas/pics/.hist/)
    hist: /mnt/nas/cache/pics/  # can be absolute path
    landmark: me.jpg  # /mnt/nas/pics/me.jpg must be readable to enable db
    landmark: info/a.txt^=ok  # and this textfile must start with "ok"
```