Translation of reference/introduction started

Author: MJ-Curtido

TRANSLATORS

@@ -170,6 +170,7 @@ Luis Sánchez (@LuisAISanchez)
 Maia
 Manu de Frutos Vila (@manudefrutosvila)
 Manuel Garrido
+Manuel Jesus Curtido Rosado (@MJ-Curtido)
 Manuel Kaufmann (@humitos)
 Manuel Quiñones (@manuq)
 Manuel Ramos (@manuelramos)

reference/introduction.po

@@ -249,6 +249,10 @@ msgid ""
 "defined) followed by a colon, ``:``. The definition to the right of the "
 "colon uses the following syntax elements:"
 msgstr ""
+"TODO: continuar por aquí"
+"Each rule begins with a name (which identifies the rule that's being "
+"defined) followed by a colon, ``:``. The definition to the right of the "
+"colon uses the following syntax elements:"
 
 #: ../Doc/reference/introduction.rst:116
 msgid ""