closures - uninitialized vs undefined

in [this article](https://javascript.info/closure), we are discussing lexical environments, and the scope of variables.
upon initialization, variables are defined as `` because "[the engine knows about the variable, but it cannot be referenced until it has been declared with `let`](https://javascript.info/closure#step-1-variables)"

later in the article, when referencing nested lexical environments in functions, a variable is initialized as `undefined`. from my understanding, this is incorrect, as the engine knows about the variable, but is not referenced yet since it hasn't been declared.

i believe that we need to change the following SVG's to reflect this change:
https://github.com/javascript-tutorial/en.javascript.info/blob/master/1-js/06-advanced-functions/03-closure/lexenv-nested-makecounter-2.svg
https://github.com/javascript-tutorial/en.javascript.info/blob/master/1-js/06-advanced-functions/03-closure/lexenv-nested-makecounter-3.svg

if this is an incorrect assumption, please help me understand why it's undefined instead of uninitialized! i'd love to learn more about how this all works.

Inizia con le sezioni sull’ambiente lessicale e sulle funzioni annidate dell’articolo sulle closure, quindi confronta le etichette in lexenv-nested-makecounter-2.svg e lexenv-nested-makecounter-3.svg. Verifica se i diagrammi debbano distinguere da undefined e aggiorna questi SVG solo se il comportamento di JavaScript supporta la correzione proposta.

Scritto dal modello di indicizzazione a partire dal testo della issue.