docs: use python to highlight requirements and use more content tabs (#6549)

## Summary

It appears that using `python` for code blocks containing requirements
works quite well.

![Screenshot from 2024-08-23
23-23-05](https://github.com/user-attachments/assets/38c92ef7-1f5e-40eb-8ea4-7024c8180bc4)

![Screenshot from 2024-08-23
23-23-31](https://github.com/user-attachments/assets/940dc7d5-22a8-4cd8-b54a-d56542d4345c)

Also using more content tabs for cases where we need to differentiate
macOS/Linux from Windows.

## Test Plan

Local run of the documentation.

docs/reference/resolver-internals.md

@@ -70,7 +70,7 @@ was usually limited to single environment, which one specific architecture, oper
 version, and Python implementation. Some packages use contradictory requirements for different
 environments, for example:
 
-```text
+```python
 numpy>=2,<3 ; python_version >= "3.11"
 numpy>=1.16,<2 ; python_version < "3.11"
 ```
@@ -85,7 +85,7 @@ In the above example, the partial solution would be split into two resolutions,
 If markers overlap or are missing a part of the marker space, the resolver splits additional times —
 there can be many forks per package. For example, given:
 
-```text
+```python
 flask > 1 ; sys_platform == 'darwin'
 flask > 2 ; sys_platform == 'win32'
 flask