docs: replace `FOO by :term:FOO` where possible

If a variable has a glossary entry and some rST files write about those
variables, it's better to point to the glossary entry instead of just
highlighting it by surrounding it with two tick quotes.

This was automated by the following python script:
"""
import re
from pathlib import Path

with open('objects.inv.txt', 'r') as f:
    objects = f.readlines()

with open('bitbake-objects.inv.txt', 'r') as f:
    objects = objects + f.readlines()

re_term = re.compile(r'variables.html#term-([A-Z_0-9]*)')
terms = []

for obj in objects:
    match = re_term.search(obj)
    if match and match.group(1):
        terms.append(match.group(1))

for rst in Path('.').rglob('*.rst'):
    with open(rst, 'r') as f:
        content = "".joing(f.readlines())
    for term in terms:
        content = re.sub(r'``({})``(?!.*\s*[~-]+)'.format(term), r':term:`\1`', content)

    with open(rst, 'w') as f:
        f.write(content)
"""

(From yocto-docs rev: ba49d9babfcb84bc5c26a68c8c3880a1d9c236d3)

Signed-off-by: Quentin Schulz <foss@0leil.net>
Reviewed-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Reviewed-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/migration-guides/migration-2.4.rst

@@ -63,7 +63,7 @@ occurred:
 
    -  The ``ionice`` program is now packaged in a separate
       "util-linux-ionice" package. The main ``util-linux`` package has a
-      recommended runtime dependency (i.e. ``RRECOMMENDS``) on the
+      recommended runtime dependency (i.e. :term:`RRECOMMENDS`) on the
       ``util-linux-ionice`` package.
 
 -  ``initscripts``: The ``sushell`` program is now packaged in a
@@ -71,7 +71,7 @@ occurred:
    systems to pull ``sushell`` in when ``selinux`` is enabled. The
    change also eliminates needing to pull in the entire ``initscripts``
    package. The main ``initscripts`` package has a runtime dependency
-   (i.e. ``RDEPENDS``) on the ``sushell`` package when "selinux" is in
+   (i.e. :term:`RDEPENDS`) on the ``sushell`` package when "selinux" is in
    ``DISTRO_FEATURES``.
 
 -  ``glib-2.0``: The ``glib-2.0`` package now has a recommended