slightly better readme

README.md

@@ -8,7 +8,26 @@ cargo install --locked fif
 ```
 
 ## Usage
-<!-- TODO: documentation 0uo -->
+See `fif --help` for more.
+
+### The basics
+The simplest way to use fif looks like this:
 ```bash
-fif --help
+fif -E images ~/Pictures
-```
+```
+
+This command will scan all of the files with extensions used by image files (.jpg, .png, etc) in your `~/Pictures`
+directory.
+
+You can also manually specify a set of extensions to use:
+
+```bash
+fif -e jpeg,jpg,zip,docx ~/Documents
+```
+
+By default, fif will output a bash script that can be used to fix all the files it found with incorrect file extensions.
+You might find it useful to output this script to a file (rather than to stdout):
+
+```bash
+fif -E images ~/Pictures > output.sh
+```

clippy.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+fd -e rs -x touch {}
+cargo clippy -- \
+ -W clippy::nursery \
+ -W clippy::perf \
+ -W clippy::pedantic \
+ -W clippy::complexity \
+ -W clippy::cargo \
+ -A clippy::unused_io_amount \
+ -A clippy::redundant_closure_for_method_calls \
+ -A clippy::shadow_unrelated \
+
+# ALLOWS:
+# unused_io_amount: there are two places where i want to read up to X bytes and i'm fine with getting less than that
+# redundant_closure...: the alternative is often much more verbose
+# shadow_unrelated: sometimes things that seem unrelated are actually related ;)
+