Fix broken link in readthedocs

[sufikaur]

Fixes/Resolves:

Issue 1705
(replace this with the issue # fixed or resolved, if no issue exists then a brief statement of what this PR does)

Summary/Motivation:

Parallel Manager link is broken on this page: https://watertap.readthedocs.io/en/latest/technical_reference/tools/index.html

Changes proposed in this PR:

• Fix path to link for parallel manager

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