CONTRIBUTING.md: update to use injected properties

See #132

CONTRIBUTING.md

@@ -22,18 +22,19 @@ interpreted as described in [RFC 2119](https://www.ietf.org/rfc/rfc2119.txt).
    be included either in the `README.md` or as comments in the configuration.
 6. A blocklet's suggested command SHOULD be of the form
    `command=$SCRIPT_DIR/myscript [args...]` even
-   if the script is a single line.
+   if the script is a single line. The [args...] SHOULD be empty, in favor of
+   using injected properties.
 7. The command file (`myscript` above) SHOULD be the entirety of the
    executable part of your blocklet, i.e. your code is a single script.
 8. The command file's name, SHOULD match the name of the 
    containing directory. E.g. `myscript/myscript`
    is a good name, but `myscript/yourscript` is not.
 9. A blocklet SHOULD NOT have a separate non `i3blocks.conf` configuration
    file. Any extra configuration (e.g. default colors, paths, etc.) SHOULD be 
-   contained in the command file near the top.
+   injected properties.
 10. A blocklet MUST include at least one screenshot of what it looks like in
    action.
-11. A blocklet MAY require building, but if it does the build process SHOULD be
+11. A blocklet MAY require building/compiling, but if it does the build process SHOULD be
    as simple as possible (preferably nothing more than running `make`)
 12. A blocklet SHOULD include a `LICENSE` file.
 13. A blocklet MAY include a `.gitignore` file.
@@ -60,7 +61,7 @@ interpreted as described in [RFC 2119](https://www.ietf.org/rfc/rfc2119.txt).
 5. Commit details SHOULD write `Fixes: [issue]` or `Closes: [issue]` if
    the commit is meant to fix/close an issue on the issues page.
 6. A pull request SHOULD contribute significant change to exactly one
-   blocklet. A bug fix or new command line option will usually be considered 
+   blocklet. A bug fix or new injected property will usually be considered 
    a significant change.
 
 # Example workflow
@@ -75,14 +76,14 @@ In case you have never made a pull request before, here is an example workflow.
 3. You fork the i3blocks-contrib repository on github, and clone your fork of
    i3blocks-contrib onto your computer with `git clone [your fork here]`.
 4. You copy your `myscript` directory to the top level of the cloned
-   i3blocks-contrib directory and change to the top level directory.
+   i3blocks-contrib directory and `cd` to the top level directory.
 5. You `git add myscript` to tell git to track your blocklet's directory, you 
    will need to do this before every commit.
 6. You `git commit` and leave a commit message of the form
    `myscript: add myscript, a short description of myscript`
 7. Perhaps you make a few last minute changes, and add another commit.
 8. You squash your commits into one with `git rebase -i` and follow the
-   instruction, leaving only your first commit and commits that were already 
+   instructions, leaving only your first commit and commits that were already 
    there unsquashed.
 9. You push your changes to your fork on github with `git push`.
 10. You navigate to vivien's i3blocks-contrib, click "pull requests" and