Standardize file/directory placeholders

[EmilyGraceSeville7cf]

Use "<path/to/file>" and "<path/to/directory>" instead of not standardized variations like <file>, <dir> and <directory>.

Users should have the same the best experience on all pages.

[chrisallenlane]

@EmilySeville7cfg, I would actually rather avoid using <path/to/file>.

In docopt, the placeholders (like <foo>) are names, so it's not correct to put paths here.

Alternatively, something like <infile>, <outfile>, <file-1>, <file-2>, etc, might make sense, because those are descriptive.

Please let me know if this makes sense. Thanks.

[EmilyGraceSeville7cf]

Yeah, such way of presenting paths makes sense. I've updated #194 PR according to your comment. :)

[edgester]

@chrisallenlane , How do we resolve issue #190? What is the preferred way to do placeholders for the most common ones? For example, when the find command, would we use find <directory> ... or something else. I'm just looking to be consistent. I like what @EmilySeville7cfg is doing with cleaning up.

[EmilyGraceSeville7cf]

@edgester, I've proposed these rules for placeholders:

• For path placeholders use <in-file>, <out-file>, or <file>. Almost the same applies to directories
  but instead of term file dir term is used.

Initially I've tried to apply TlDr page placeholder syntax here but this idea was declined so I've suggested alternatives. ;)

[EmilyGraceSeville7cf]

I am closing this PR to make project maintainer pay attention for it.