Fix indentation in doc.

[vincentmr]

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Context:

Description of the Change:

Benefits:

Possible Drawbacks:

Related GitHub Issues:

[codecov]

Codecov Report

Merging #456 (919adf5) into master (58c9e1c) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #456   +/-   ##
=======================================
  Coverage   99.82%   99.82%           
=======================================
  Files          50       50           
  Lines        4667     4667           
=======================================
  Hits         4659     4659           
  Misses          8        8           

Impacted Files	Coverage Δ
pennylane_lightning/lightning_qubit.py	99.14% <ø> (ø)
pennylane_lightning/_version.py	100.00% <100.00%> (ø)

[AmintorDusko]

Looks good, thank you for that @vincentmr.
For those of you reviewing this PR, here goes a direct link for the affected part.

[AmintorDusko]

Before this fix the documentation was showing:

[mlxd]

Thanks for the quick fix @vincentmr