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-2.3.rst

@@ -35,7 +35,7 @@ Consider the following:
    As an example, see the ``dbus`` recipe. You will see that this recipe
    has a ``pkg_postinst`` that calls ``systemctl`` if "systemd" is in
    :term:`DISTRO_FEATURES`. In the example,
-   ``systemd-systemctl-native`` is added to ``PACKAGE_WRITE_DEPS``,
+   ``systemd-systemctl-native`` is added to :term:`PACKAGE_WRITE_DEPS`,
    which is also conditional on "systemd" being in ``DISTRO_FEATURES``.
 
 -  Examine Recipes that Use ``SSTATEPOSTINSTFUNCS``: You need to
@@ -136,7 +136,7 @@ The following changes to scripts took place:
    removed because the script was found to be deleting files it should
    not have, which lead to broken build trees. Rather than trying to
    delete portions of :term:`TMPDIR` and getting it wrong,
-   it is recommended that you delete ``TMPDIR`` and have it restored
+   it is recommended that you delete :term:`TMPDIR` and have it restored
    from shared state (sstate) on subsequent builds.
 
 -  ``wipe-sysroot``: The ``wipe-sysroot`` script has been removed as
@@ -200,10 +200,10 @@ The following changes took place for BitBake:
    section in the BitBake
    User Manual for additional information.
 
--  ``BB_SETSCENE_VERIFY_FUNCTION`` and ``BB_SETSCENE_VERIFY_FUNCTION2``
+-  ``BB_SETSCENE_VERIFY_FUNCTION`` and :term:`BB_SETSCENE_VERIFY_FUNCTION2`
    Removed: Because the mechanism they were part of is no longer
    necessary with recipe-specific sysroots, the
-   ``BB_SETSCENE_VERIFY_FUNCTION`` and ``BB_SETSCENE_VERIFY_FUNCTION2``
+   ``BB_SETSCENE_VERIFY_FUNCTION`` and :term:`BB_SETSCENE_VERIFY_FUNCTION2`
    variables have been removed.
 
 .. _migration-2.3-absolute-symlinks:
@@ -426,10 +426,10 @@ The following miscellaneous changes have occurred:
 
 -  If the :term:`DISTRO_VERSION` value contains
    the value of the :term:`DATE` variable, which is the
-   default between Poky releases, the ``DATE`` value is explicitly
+   default between Poky releases, the :term:`DATE` value is explicitly
    excluded from ``/etc/issue`` and ``/etc/issue.net``, which is
    displayed at the login prompt, in order to avoid conflicts with
-   Multilib enabled. Regardless, the ``DATE`` value is inaccurate if the
+   Multilib enabled. Regardless, the :term:`DATE` value is inaccurate if the
    ``base-files`` recipe is restored from shared state (sstate) rather
    than rebuilt.
 
@@ -451,7 +451,7 @@ The following miscellaneous changes have occurred:
    tools.
 
 -  The ``USE_LDCONFIG`` variable has been replaced with the "ldconfig"
-   ``DISTRO_FEATURES`` feature. Distributions that previously set::
+   :term:`DISTRO_FEATURES` feature. Distributions that previously set::
 
       USE_LDCONFIG = "0"
 
@@ -494,12 +494,12 @@ The following miscellaneous changes have occurred:
    information.
 
 -  All native and nativesdk recipes now use a separate
-   ``DISTRO_FEATURES`` value instead of sharing the value used by
+   :term:`DISTRO_FEATURES` value instead of sharing the value used by
    recipes for the target, in order to avoid unnecessary rebuilds.
 
-   The ``DISTRO_FEATURES`` for ``native`` recipes is
+   The :term:`DISTRO_FEATURES` for ``native`` recipes is
    :term:`DISTRO_FEATURES_NATIVE` added to
-   an intersection of ``DISTRO_FEATURES`` and
+   an intersection of :term:`DISTRO_FEATURES` and
    :term:`DISTRO_FEATURES_FILTER_NATIVE`.
 
    For nativesdk recipes, the corresponding variables are