chore: add language identifiers, fix code sample

the config sample didn't make any sense, broke it up into lines

src/content/docs/apm/agents/python-agent/python-agent-api/registerdatasource-python-agent-api.mdx

@@ -14,7 +14,7 @@ redirects:
 
 ## Syntax
 
-```
+```py
 newrelic.agent.register_data_source(source, application=None, name=None, settings=None, **properties)
 ```
 
@@ -43,8 +43,15 @@ For more about these fields and some general usage tips, see [Pre-aggregated met
 <Callout variant="tip">
   You can also accomplish the same result using [agent configuration](/docs/agents/python-agent/installation-configuration/python-agent-configuration), which doesn't require you to change your code. To add the data source in this way, add a section in the config file with the prefix `data-source:`, followed by a unique value to distinguish the section for that of another data source if more than one is specified. Here's an example:
 
-  ```
-  [data-source:memory-usage]enabled = truefunction = samplers:memory_metrics# application = ...# name = ...[data-source:cpu-usage]enabled = truefunction = samplers:CPUMetricsDataSource# application = ...# name = ...
+  ```ini
+  [data-source:memory-usage]enabled = true
+  function = samplers:memory_metrics
+  # application = ...
+  # name = ...
+  [data-source:cpu-usage]enabled = true
+  function = samplers:CPUMetricsDataSource
+  # application = ...
+  # name = ...
   ```
 
   If the data source was specified by a function, then the name would be `module:function`. If a class, then it would be: `module:class`. The module must be able to be found using the Python module search path.
@@ -142,7 +149,7 @@ None.
 
 Here's an example of some app code that generates custom metric data:
 
-```
+```py
 @newrelic.agent.data_source_generator(name='External') 
 def services(): 
     # code goes here
@@ -159,7 +166,7 @@ if __name__ == '__main__':
 
 ### Memory usage from data source [#data-source-memory]
 
-```
+```py
 import psutil
 import os