docs: drop unknown field (#1088)

hishamhm · web-flow · commit 7b3eaf76258d · 2026-02-03T21:18:44.000-03:00
See error at https://github.com/teal-language/tl/actions/runs/21642448018/job/62385583278 Not sure how that worked before and stopped working...
diff --git a/docs/book.toml b/docs/book.toml
@@ -1,6 +1,5 @@
 [book]
 authors = ["Hisham Muhammad", "Teal project contributors"]
 language = "en"
-multilingual = false
 src = "src"
 title = "The Teal Programming Language"
