Merge pull request #2228 from Sefaria/quick-url-fix

fix(errors): Update URL to match new devportal slug

Author: yitzhakc

sefaria/system/exceptions.py

@@ -108,5 +108,5 @@ def __init__(self, book_ref):
                         f"'{book_ref}' is a \'complex\' book-level ref. We only support book-level "
                         f"refs in cases of texts with a 'simple' structure. To learn more about the "
                         f"structure of a text on Sefaria, "
-                        f"see: https://developers.sefaria.org/docs/the-schema-of-a-simple-text")
+                        f"see: https://developers.sefaria.org/docs/the-structure-of-a-simple-text")
         super().__init__(self.message)