feat(script): skip dependency installation by default (ayamir#1114)

IMO the default choice for dependency installation in `install.ps1`
is a bit misleading (see Discussion ayamir#1106). afaik most users won't
even "visit" the dynamic provider feature of Neovim, and those who
know what they're doing can still continue with the dependency
installation by typing `Y/y`. So I think a more reasonable default
should be `N` (i.e. skipping provider installation altogether.)

scripts/install.ps1

@@ -242,7 +242,7 @@ function confirm_dep_inst ([Parameter(Mandatory = $True)][ValidateNotNullOrEmpty
 		$_opt_yes = New-Object System.Management.Automation.Host.ChoiceDescription "&Yes","Will install $PkgName dependencies"
 		$_opt_no = New-Object System.Management.Automation.Host.ChoiceDescription "&No","Will SKIP installing $PkgName dependencies"
 
-		$USR_CHOICE = $Host.ui.PromptForChoice($_title,$_message,[System.Management.Automation.Host.ChoiceDescription[]]($_opt_yes,$_opt_no),0)
+		$USR_CHOICE = $Host.ui.PromptForChoice($_title,$_message,[System.Management.Automation.Host.ChoiceDescription[]]($_opt_yes,$_opt_no),1)
 		if ($USR_CHOICE -eq 0) {
 			return $True
 		} else {