docs: adding new tutorial on how to handle heaptrack with nim waku

[Ivansete-status]

Description

As per the issue "Heap analysis using heaptrack" we are adding a new tutorial that explains how to interact with heaptrack and nimwaku

Heaptrack is a memory analysis tool very useful to get a good insight of the underlying memory usage.

In this tutorial we describe the next "how to's":

• get and build locally the heaptrack tool (Ubuntu.).
• generate a heaptrack memory report.
• analyse the resulting report.
• create docker image with both heaptrack plus wakunode2

[jm-clius]

Great work on this (both getting heaptrack working properly and documenting it in a tutorial)!🙌 Consider using semantic breaks between lines and clauses: https://sembr.org/

[alrevuelta]

great thanks for all the work with this!