tcslog-tools 0.1.7

Command-line tools for inspecting tcslog segment files: tcslog-dump and tcslog-dumphdr
Documentation
Neither tool changed. What moved is where the documentation is: the crate
now has a library target carrying the README as its own documentation, so
docs.rs has a page for the crate rather than only one page per binary.

Requires `tcslog` 0.2.

### Added

- A library target carrying the README as the crate's documentation, which is
  what docs.rs renders. These are two command-line programs, so there had been
  no library to document and so no docs.rs page for the crate at all -- only
  one per binary, which is not where anyone looks first. The target exports
  nothing and no dependent has reason to link it. The README is included
  rather than copied, so the page cannot drift from what crates.io shows.
- The README points at the documentation: `docs/tcslog-tools.rst` for these
  tools at greater length, and `docs/tcslog.rst` in the `tcslog` repository
  for the log format they read and the recovery rules they report on, those
  belonging to the library rather than here.