svgbob should run after gettext (#429)

svgbob translates `_text_` into `*text*`, which makes gettext fail to
translate paragraphs with `_text_`.

Co-authored-by: Jooyung Han <[email protected]>

Author: jooyunghan

book.toml

@@ -20,6 +20,7 @@ renderers = ["html"]
 
 [preprocessor.svgbob]
 renderers = ["html"]
+after = ["gettext"]
 class = "bob"
 
 # Enable this preprocessor to overlay a large red rectangle on the