add documentation for insensitive setting

[michael-brueggemann]

In German, the a noun starts with an upper case (e.g. "Stadt" = "city").
In source code, a variable name normally starts with a lower case (=> "stadt"). Therefore the case sensitive setting should be disabled.
Please add in the documentation of this extension, that for German spell checking this setting is useful.

"cSpell.languageSettings": [
  {
    "locale": "de-de",
    "languageId": "*",
    "caseSensitive": false
  }
],

[S-p-Ace]

first, Thank You!
second, I think it already is 'documented' - I just kept looking in the wrong place

cSpell.caseSensitive

• false: [...] Note: Some languages like Portuguese have case sensitivity tunred on by default. You must use 'C Spell: Language Settings' to turn it off.

Maybe the 'Note:' or 'turned on by default' should be emphasized here so it isn't missed so easially when looking up if case sensitivity is turned on or not.