Add quickstart page on mid-circuit measurements (#5870)

**Context:**
The PennyLane documentation has a quickstart page on measurements, which
includes a large section about mid-circuit measurements.
With the focus on dynamic circuits and mid-circuit measurements more
generally, we would like to make the content on MCMs more visible.

**Description of the Change:**
Extracts the MCM part of the measurements quickstart and adds it as its
own quickstart page.
Adds some details on simulation techniques and polishes the content.

**Benefits:**
Visibility, documentation extent for MCMs

**Possible Drawbacks:**

**Related GitHub Issues:**

[sc-65318]

---------

Co-authored-by: Vincent Michaud-Rioux <vincentm@nanoacademic.com>

doc/development/guide/architecture.rst

@@ -8,7 +8,7 @@ PennyLane's core feature is the ability to compute gradients of variational
 quantum circuits in a way that is compatible with classical techniques such as
 backpropagation. PennyLane thus extends the automatic differentiation
 algorithms common in optimization and machine learning to include quantum and
-:doc:`hybrid computations <glossary/hybrid_computation>`.
+`hybrid computations <https://pennylane.ai/qml/glossary/hybrid_computation>`_.
 A plugin system makes the framework compatible with many quantum
 simulators or hardware devices, remote or local.
 

doc/index.rst

@@ -159,6 +159,7 @@ PennyLane is **free** and **open source**, released under the Apache License, Ve
    introduction/interfaces
    introduction/operations
    introduction/measurements
+   introduction/dynamic_quantum_circuits
    introduction/templates
    introduction/inspecting_circuits
    introduction/compiling_circuits