💄 fix: adapt footnotes styling for zola 0.19.x & 0.20.x

Also makes code tags slightly smaller (to match the font) in footnotes.

Zola 0.20.0 wraps footnotes in a <footer> tag, which broke existing styles.
This change makes the CSS selectors work with both old (<ol>) and new
(<footer>) HTML structures while maintaining the same visual appearance.

content/blog/markdown/index.ca.md

@@ -105,4 +105,6 @@ A Rust, declares una variable mutable amb `let mut x = 5;`, mentre que a Python,
 >
 > — Mercè Rodoreda, La plaça del Diamant
 
+---
+
 [^1]: I aquí tens un exemple de nota a peu de pàgina!

content/blog/markdown/index.es.md

@@ -105,4 +105,6 @@ En Rust, declaras una variable mutable con `let mut x = 5;`, mientras que en Pyt
 >
 > — Miguel de Unamuno, Niebla
 
+---
+
 [^1]: ¡Y aquí tienes un ejemplo de una nota al pie de página!

content/blog/markdown/index.md

@@ -105,4 +105,6 @@ In Rust, you declare a mutable variable with `let mut x = 5;`, whereas in Python
 >
 > — Charlie Kaufman, Synecdoche, New York
 
+---
+
 [^1]: And here's an example of a footnote!