manuals: suppress excess use of "following" word

To simplify the style, replace "Following is" and "Following are"
by "here is" and "here are", sounding more natural.

In some cases, also go further by simplifying "Here are/is xxx"
by "xxx are/is" when the "are" or "is" are not two far at
the end of the sentence.

In some cases too, completely remove the sentence, when
it's redundant with the preceding title.

(From yocto-docs rev: 2539f1b9cbf9bdd40eff93c6522dc76133debed7)

Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
CC: Daniel Ammann <daniel.ammann@bytesatwork.ch>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

documentation/dev-manual/start.rst

@@ -36,7 +36,7 @@ particular working environment and set of practices.
     equipment together and set up your development environment's
     hardware topology.
 
-    Here are possible roles:
+    Possible roles are:
 
     -  *Application Developer:* This type of developer does application
        level work on top of an existing software stack.
@@ -99,7 +99,7 @@ particular working environment and set of practices.
 
 5.  *Set up the Application Development Machines:* As mentioned earlier,
     application developers are creating applications on top of existing
-    software stacks. Following are some best practices for setting up
+    software stacks. Here are some best practices for setting up
     machines used for application development:
 
     -  Use a pre-built toolchain that contains the software stack
@@ -118,7 +118,7 @@ particular working environment and set of practices.
 
 6.  *Set up the Core Development Machines:* As mentioned earlier, core
     developers work on the contents of the operating system itself.
-    Following are some best practices for setting up machines used for
+    Here are some best practices for setting up machines used for
     developing images:
 
     -  Have the :term:`OpenEmbedded Build System` available on