tree-wide: make doc-strings RST-compliant

sphinx became stricter when handling interpreted text without a role,
e.g. "`foo`" since [1], see [2]. This results in errors such as:

  sphinx.errors.SphinxError: cannot determine default role!

In the past, heuristics were used to determine how
to format the text (inline code, italic, ..).

In labgrid, interpreted text without a role is used inconsistently. Most
times it was actually meant to be either inline code ("``foo``"), italic
text or links to docs sections or class definitions.
Fix all such occurrences with explicit variants that actually make sense
in their respective contexts.

[1] sphinx-doc/sphinx@114093c
[2] sphinx-doc/sphinx#13904

Signed-off-by: Bastian Krause <bst@pengutronix.de>

Author: Bastian-Krause

labgrid/driver/dockerdriver.py

@@ -12,9 +12,9 @@
 
 
 class PullPolicy(Enum):
-    """Pull policy for the `DockerDriver`.
+    """Pull policy for the DockerDriver.
 
-    Modelled after `podman run --pull` / `docker run --pull`.
+    Modelled after ``podman run --pull`` / ``docker run --pull``.
 
     * always: Always pull the image and throw an error if the pull fails.
     * missing: Pull the image only when the image is not in the local
@@ -60,7 +60,7 @@ class DockerDriver(PowerProtocol, Driver):
         bindings (dict): The labgrid bindings
     Args passed to docker.create_container:
         image_uri (str): The uri of the image to fetch
-        pull (str): Pull policy. Default policy is `always` for backward
+        pull (str): Pull policy. Default policy is ``always`` for backward
         compatibility concerns
         command (str): The command to execute once container has been created
         volumes (list): The volumes to declare

labgrid/driver/power/ubus.py

@@ -3,7 +3,7 @@
   handy if devices are connected to a PoE switch running OpenWrt.
 
   The URL given in hosts in exporter.yaml must accept unauthenticated UBUS
-  calls for the two `poe` calls `info` and `manage`.
+  calls for the two ``poe`` calls ``info`` and ``manage``.
 
   Further information is availbe at https://openwrt.org/docs/techref/ubus#acls
 

labgrid/pytestplugin/fixtures.py

@@ -113,7 +113,7 @@ def env(request, record_testsuite_property):
 
 @pytest.fixture(scope="session")
 def target(env):
-    """Return the default target `main` configured in the supplied
+    """Return the default target "main" configured in the supplied
     configuration file."""
     target = env.get_target()
     if target is None:
@@ -124,7 +124,7 @@ def target(env):
 
 @pytest.fixture(scope="session")
 def strategy(request, target):
-    """Return the Strategy of the default target `main` configured in the
+    """Return the Strategy of the default target "main" configured in the
     supplied configuration file."""
     try:
         strategy = target.get_driver("Strategy")