Add Docker install instructions for MacOS + Ubuntu + windows in hello world docs example

[nmwalsh]

No description provided.

[coveralls]

Pull Request Test Coverage Report for Build 1037

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 52 unchanged lines in 15 files lost coverage.
• Overall coverage remained the same at 87.88%

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Files with Coverage Reduction	New Missed Lines	%
datmo/cli/command/base.py	1	93.98%
datmo/snapshot.py	1	83.49%
datmo/cli/command/datmo_command.py	2	100.0%
datmo/core/util/i18n.py	2	100.0%
datmo/cli/command/run.py	2	81.57%
datmo/core/controller/file/driver/local.py	2	91.95%
datmo/logger.py	2	92.59%
datmo/cli/command/snapshot.py	2	100.0%
datmo/cli/command/session.py	2	95.7%
datmo/core/controller/code/driver/file.py	2	94.12%

Totals
Change from base Build 1033:	0.0%
Covered Lines:	4133
Relevant Lines:	4703

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💛 - Coveralls

[shabazpatel]

@nmwalsh Can you also add it for windows? https://github.com/datmo/hello-world