Update some docs

CUSTOMIZATION.md

@@ -168,12 +168,12 @@ As output, this script should emit whatever the programs it calls emit.
 - 255: error internal to the script in question
 
 (FIXME: Unsurprisingly, `gofmt` is the only tool I've tested so far that gets
-this right.  That a file should be reformatted isn't an exceptional condition,
-so there's no good reason to signal failure here.
+this right.  It isn't an exceptional condition when a file should be
+reformatted, so there's no good reason to signal failure here.
 
 Even less unsurprisingly, Laravel pint gets it worse than all the others I
-checked; it doesn't distinguish misformatted files from files with actual
-syntax errors.
+checked; it doesn't distinguish files that need to be reformatted from files
+with actual syntax errors.
 
 Anyway, `gofmt` is the obviously the model to follow.  So we should
 probably drop `1`.)

DEVELOPMENT.md

@@ -24,11 +24,13 @@ request anyway and we can work on getting it up to snuff.
 - Be easy to configure.
 - Be clearly documented.  Remember that many programmers are working in
   high-stress situations.  Documentation that is incomplete, unclear, or cute
-  will make things even worse for them.  Use English correctly and, to the
+  makes things even worse for them.  Use English correctly and, to the
   extent possible, unambiguously.
 
 ## Non-goals
 
+- We don't want to do anything with warnings etc that aren't specifically
+  formatting-related
 
 # Wishlist
 
@@ -46,12 +48,16 @@ request anyway and we can work on getting it up to snuff.
   conclusion.
 - Write a doctor command to identify potential issues (you'd probably run it
   similarly to how you run the install script, but `s/install/doctor`).
+- Create a nix setup that includes all the tools as fallbacks
+- Cache file type sniffing results?  How?
 
 # Problems
 
 - It would probably be better if we wrote reformatted code to temp files and
   atomically renamed them.  This might mean that the tool-specific programs
-  should emit diffs rather than working silently as they currently do.
+  should emit diffs rather than working silently as they currently do.  The
+  rationale is that this makes it a lot easier to atomically apply two or more
+  fixers.
 - It probably doesn't work on Windows as-is.
 - There are probably some Linuxisms and maybe even some recentbashisms.
 - It doesn't work with tramp.

README.md

@@ -1,4 +1,4 @@
-would-reformat - automatic reformatting for emacs without being annoying
+would-reformat - automatic reformatting for emacs (and maybe other editors) without being annoying
 
 # Motivation
 
@@ -38,9 +38,13 @@ saving a file and to run `do-reformat.sh` when you hit `<F1>`.
 - typescript
 - vue
 
-Out of the box, python uses `isort` and `black`, go uses `gofmt`, and dart
-uses `dart format`.  The rest use `prettier`.  Adding new programming
-languages is easy, assuming they have a formatter with a dry run mode.
+Out of the box, for python we use `isort` and `black`, for go we use `gofmt`,
+for dart we use `dart format`, for rust we use `rustfmt`, and for everything
+else we use `prettier`.
+
+Adding suuport for other programming languages is easy, assuming they have a
+formatter with a dry run mode.  And even if they don't it shouldn't be that
+bad.
 
 # Installation