Update readme with build + fonts dir instructions

README.md

@@ -1,3 +1,13 @@
 # kids-stuff
 
 custom made resources, worksheets, etc for kids!
+
+## building
+
+You'll need to install `typst`, then build any file like so:
+
+```
+typst compile --font-path ./fonts path/to/thing.typ path/to/thing.pdf
+# e.g.,
+typst compile --font-path ./fonts morning-checklist/morning-checklist.typ morning-checklist/morning-checklist.pdf
+```