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/overview-manual/yp-intro.rst b/documentation/overview-manual/yp-intro.rst
index a2e0862459..4e3b7c3250 100644
--- a/documentation/overview-manual/yp-intro.rst
+++ b/documentation/overview-manual/yp-intro.rst
@@ -842,7 +842,7 @@ helpful for getting started:
    distribution.
 
    Another point worth noting is that historically within the Yocto
-   Project, recipes were referred to as packages - thus, the existence
+   Project, recipes were referred to as packages --- thus, the existence
    of several BitBake variables that are seemingly mis-named, (e.g.
    :term:`PR`,
    :term:`PV`, and