Before, pressing <Enter> when completions were visible would execute the
selected completion. As soon as completions were provided, the first
item would be selected. This could cause issues e.g. when changing
Previously, this would have selected the first folder in the list. Now,
since <Tab>, <C-n>, etc have not been pressed to select the first
completion, the command above simply executes `:cf `.
To accomplish this, a "no-op completion" has been added at index -1.