Guide to create custom models in Spanish (#17158)

* file copied and toctree updated

* Intro and configuration translated

* model section translated

* enter hotfix

* Translation over, correction pending

* Typos and corrections

* Update docs/source/es/create_a_model.mdx

Co-authored-by: Omar U. Espejel <espejelomar@gmail.com>

* Update docs/source/es/create_a_model.mdx

Co-authored-by: Omar U. Espejel <espejelomar@gmail.com>

* Update docs/source/es/create_a_model.mdx

Co-authored-by: Omar U. Espejel <espejelomar@gmail.com>

* Update docs/source/es/create_a_model.mdx

Co-authored-by: Omar U. Espejel <espejelomar@gmail.com>

Co-authored-by: Omar U. Espejel <espejelomar@gmail.com>

docs/source/es/_toctree.yml

@@ -21,6 +21,8 @@
 - sections:
   - local: fast_tokenizers
     title: Usa tokenizadores de 🤗 Tokenizers
+  - local: create_a_model
+    title: Crea una arquitectura personalizada
   - sections:
     - local: language_modeling
       title: Modelado de lenguaje
@@ -31,7 +33,4 @@
 - sections:
   - local: philosophy
     title: Filosofía
-  title: Guías conceptuales
-
-
-
+  title: Guías conceptuales