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/migration-guides/migration-3.1.rst b/documentation/migration-guides/migration-3.1.rst
index e3fdbbe425..cc788efeba 100644
--- a/documentation/migration-guides/migration-3.1.rst
+++ b/documentation/migration-guides/migration-3.1.rst
@@ -200,7 +200,7 @@ Packaging changes
 -----------------
 
 -  ``intltool`` has been removed from ``packagegroup-core-sdk`` as it is
-   rarely needed to build modern software - gettext can do most of the
+   rarely needed to build modern software --- gettext can do most of the
    things it used to be needed for. ``intltool`` has also been removed
    from ``packagegroup-core-self-hosted`` as it is not needed to for
    standard builds.