manuals: replace hyphens with em dashes

Fix some hyphens being improperly used as em dashes.
See https://www.grammarly.com/blog/hyphens-and-dashes/

Using em dashes may also allow Sphinx to hyphenate
and break lines in the best way.

Note that the first character after an em dash not
supposed to be capitalized, unless a specific
rule applies, typically when what follows is a proper noun.

Fix a few misuses of parentheses in following text.

(From yocto-docs rev: 5918f019f63f6e820b1168f4cc001faa1d1cdc6f)

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/documentation/kernel-dev/concepts-appx.rst b/documentation/kernel-dev/concepts-appx.rst
index b3a2f3abbf..63c5124a57 100644
--- a/documentation/kernel-dev/concepts-appx.rst
+++ b/documentation/kernel-dev/concepts-appx.rst
@@ -117,7 +117,7 @@ upstream Linux kernel development and are managed by the Yocto Project
 team's Yocto Linux kernel development strategy. It is the Yocto Project
 team's policy to not back-port minor features to the released Yocto
 Linux kernel. They only consider back-porting significant technological
-jumps - and, that is done after a complete gap analysis. The reason
+jumps --- and, that is done after a complete gap analysis. The reason
 for this policy is that back-porting any small to medium sized change
 from an evolving Linux kernel can easily create mismatches,
 incompatibilities and very subtle errors.