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.

Comece pelas seções sobre ambiente léxico e funções aninhadas do artigo sobre closures e, em seguida, compare os rótulos em lexenv-nested-makecounter-2.svg e lexenv-nested-makecounter-3.svg. Verifique se os diagramas devem distinguir de undefined e atualize esses SVGs somente se o comportamento do JavaScript der suporte à correção proposta.

Escrita pelo modelo de indexação a partir do texto da issue.