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, 2 deletions

diff --git a/documentation/migration-guides/migration-3.3.rst b/documentation/migration-guides/migration-3.3.rst
index d65f1c7b1f..aba5c4237c 100644
--- a/documentation/migration-guides/migration-3.3.rst
+++ b/documentation/migration-guides/migration-3.3.rst
@@ -13,11 +13,10 @@ Minimum system requirements
 You will now need at least Python 3.6 installed on your build host. Most recent
 distributions provide this, but should you be building on a distribution that
 does not have it, you can use the ``buildtools-tarball`` (easily installable
-using ``scripts/install-buildtools``) - see
+using ``scripts/install-buildtools``) --- see
 :ref:`ref-manual/system-requirements:required git, tar, python, make and gcc versions`
 for details.
 
-
 .. _migration-3.3-removed-recipes:
 
 Removed recipes