config/core.txt: fix minor issues for `core.sparseCheckoutCone`
The sparse checkout feature can be used in "cone mode" or "non-cone
mode". In this one instance in the documentation, we refer to the latter
as "non cone mode" with whitespace rather than a hyphen. Align this with
the rest of our documentation.
A few words later in the same paragraph, there's mention of "a more
flexible patterns". Drop that leading "a" to fix the grammar.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>