[DOCUMENTATION] Follow-up work on mermaid support for readthedocs.io (- WIP #413 -)

Changes in file docs/CI.md:
 * updated theme for diagrams for darkmode

Changes in file docs/Testing.md:
 * updated theme for diagrams for darkmode

Changes in file docs/conf.py:
 * fix for regression caused by last set of changes to docstrings

Author: reactive-firewall

docs/CI.md

@@ -72,6 +72,7 @@ automated analysis.
 #### How on-`workflow_run` triggers propagate
 
 ```mermaid
+%%{ init: { 'theme': 'base', 'themeVariables': { 'darkMode': true, 'primaryColor': '#3e3e3e', 'background': 'transparent', 'primaryBorderColor': 'Orange', 'lineColor': 'darkOrange', 'secondaryColor': 'transparent', 'tertiaryColor': '#030303' }} }%%
 graph TD;
     PUSH-EVENT-->CI-Build.yml;
     CI-Build.yml-->multicast-build-*;
@@ -148,6 +149,7 @@ in a single environment on CircleCI, and typically perform faster.
 #### How `push` triggers propagate on CircleCI
 
 ```mermaid
+%%{ init: { 'theme': 'base', 'themeVariables': { 'darkMode': true, 'primaryColor': '#3e3e3e', 'background': 'transparent', 'primaryBorderColor': 'Orange', 'lineColor': 'darkOrange', 'secondaryColor': 'transparent', 'tertiaryColor': '#030303' }} }%%
 graph TD;
   PUSH-EVENT-->config.yml;
   config.yml-->build;
@@ -194,6 +196,7 @@ There are many integrations with various service providers used in the Multicast
 pipeline.
 
 ```mermaid
+%%{ init: { 'theme': 'base', 'themeVariables': { 'darkMode': true, 'primaryColor': '#3e3e3e', 'background': 'transparent', 'primaryBorderColor': 'Orange', 'lineColor': 'darkOrange', 'secondaryColor': 'transparent', 'tertiaryColor': '#030303' }} }%%
 graph TD;
   PUSH-EVENT["PUSH EVENT"];
   PUSH-EVENT-->CI-Build.yml;
@@ -370,6 +373,7 @@ Logically (e.g., ignoring complexities of concurrency and trigger conditionals,
 of phases is sequential per single CI/CD linter workflow.
 
 ```mermaid
+%%{ init: { 'theme': 'base', 'themeVariables': { 'darkMode': true, 'primaryColor': '#3e3e3e', 'background': 'transparent', 'primaryBorderColor': 'Orange', 'lineColor': 'darkOrange', 'secondaryColor': 'transparent', 'tertiaryColor': '#030303' }} }%%
 sequenceDiagram
   participant Repo as Repository
 
@@ -471,6 +475,7 @@ Logically (e.g., ignoring complexities of concurrency and trigger conditionals,
 linters are all run independently per CI/CD linter workflow.
 
 ```mermaid
+%%{ init: { 'theme': 'base', 'themeVariables': { 'darkMode': true, 'primaryColor': '#3e3e3e', 'background': 'transparent', 'primaryBorderColor': 'Orange', 'lineColor': 'darkOrange', 'secondaryColor': 'transparent', 'tertiaryColor': '#030303' }} }%%
 graph TD;
     PUSH-EVENT-->bandit.yml;
     PUSH-EVENT-->codeql-analysis.yml;

docs/Testing.md

@@ -104,6 +104,7 @@ for running the various tests during the act of testing.
 > Both CI/CD and the Makefile ultimately use the same test runner under the hood.
 
 ```mermaid
+%%{ init: { 'theme': 'base', 'themeVariables': { 'darkMode': true, 'primaryColor': '#3e3e3e', 'background': 'transparent', 'primaryBorderColor': 'Orange', 'lineColor': 'darkOrange', 'secondaryColor': 'transparent', 'tertiaryColor': '#030303' }} }%%
 graph TD;
     CI["CI/CD"];
 
@@ -197,6 +198,7 @@ the selective test runner. Of course, eventually the process leads back to the n
 testing.
 
 ```mermaid
+%%{ init: { 'theme': 'base', 'themeVariables': { 'darkMode': true, 'primaryColor': '#3e3e3e', 'background': 'transparent', 'primaryBorderColor': 'Orange', 'lineColor': 'darkOrange', 'secondaryColor': 'transparent', 'tertiaryColor': '#030303' }} }%%
 sequenceDiagram
     actor user as Developer
     participant Make as Makefile
@@ -320,6 +322,7 @@ Here is how `multicast` module logging and code coverage collection are integrat
 whole testing process.
 
 ```mermaid
+%%{ init: { 'theme': 'base', 'themeVariables': { 'darkMode': true, 'primaryColor': '#3e3e3e', 'background': 'transparent', 'primaryBorderColor': 'Orange', 'lineColor': 'darkOrange', 'secondaryColor': 'transparent', 'tertiaryColor': '#030303' }} }%%
 sequenceDiagram
     actor user as Developer
     participant Make as Makefile

docs/conf.py

@@ -479,9 +479,9 @@ def linkcode_resolve(domain, info):
 			True
 			>>> type(res_text) is type(str())
 			True
-			>>> res_text is not test_text
+			>>> len(res_text) > 0
 			True
-			>>> _conf.linkcode_resolve("py", info={"module": test_text,}) is res_text
+			>>> res_text is not test_text
 			True
 			>>> _conf.linkcode_resolve("py", info={"module": ignored_input,}) is ignored_input
 			True