Add treefmt, mdformat and typos

Author: ch1bo

.gitignore

@@ -3,6 +3,3 @@
 
 # Direnv cache
 /.direnv/
-
-# Trivial flake, no need to check in lock file
-/flake.lock

flake.lock

@@ -25,6 +25,12 @@
                 mdbook-katex
                 mdbook-alerts
                 mdbook-toc
+                # formatting
+                treefmt
+                mdformat
+                python3Packages.mdformat-footnote
+                python3Packages.mdformat-gfm
+                typos
               ];
               phases = [ "unpackPhase" "buildPhase" ];
               buildPhase = ''

flake.nix

@@ -0,0 +1,12 @@
+# The formatter multiplexer - https://github.com/numtide/treefmt
+[formatter.mdformat]
+command = "mdformat"
+excludes = []
+includes = ["*.md"]
+options = ["--extensions", "gfm", "--extensions", "footnote"]
+
+[formatter.typos]
+command = "typos"
+excludes = []
+includes = ["*.md"]
+options = ["--write-changes"]