restructuring debugging tools doc (#647)

* not done; restrucutre debugging part;

* 1) fixed all developer guides 2) fixed first_nerf error 3) moved run_actions

* removed md

docs/developer_guides/debugging_tools/profiling.md

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+# Code profiling support
+
+We provide built-in performance profiling capabilities to make it easier for you to debug and assess the performance of your code.
+
+#### In-house profiler
+
+You can use our built-in profiler. By default, it is enabled and will print at the termination of the program. You can disable it via CLI using the flag `--logging.no-enable-profiler`.
+
+
+The profiler computes the average total time of execution for any function with the `@profiler.time_function` decorator.
+For instance, if you wanted to profile the total time it takes to generate rays given pixel and camera indices via the `RayGenerator` class, you might want to time its `forward()` function. In that case, you would need to add the decorator to the function.
+
+```python
+"""nerfstudio/model_components/ray_generators.py""""
+
+class RayGenerator(nn.Module):
+
+    ...
+
+    @profiler.time_function     # <-- add the profiler decorator before the function
+    def forward(self, ray_indices: TensorType["num_rays", 3]) -> RayBundle:
+        # implementation here
+        ...
+```
+
+At termination of training or end of the training run, the profiler will print out the average execution time for all of the functions that have the profiler tag.
+
+:::{admonition} Tip
+:class: info
+
+Use this profiler if there are *specific/individual functions* you want to measure the times for.
+  :::
+
+
+#### Profiling with PySpy
+
+If you want to profile the entire codebase, consider using [PySpy](https://github.com/benfred/py-spy).
+
+Install PySpy
+
+```bash
+pip install py-spy
+```
+
+To perform the profiling, you can either specify that you want to generate a flame graph or generate a live-view of the profiler.
+
+```bash
+## flame graph: with wandb logging and our inhouse logging disabled
+program="ns-train nerfacto -- --vis=wandb --logging.no-enable-profiler blender-data"
+py-spy record -o {PATH_TO_OUTPUT_SVG} $program
+```
+
+```bash
+## top-down stats: running same program configuration as above
+py-spy top $program
+```
+:::{admonition} Attention
+:class: attention
+
+In defining `program`, you will need to add an extra `--` before you specify your program's arguments.
+  :::