Fixing typos in README.md File

[iamrodrigo]

Describe what has changed in this PR
README.md was modified, 2 words typos were fixed. The first one, the docker-compose.yaml file doesn't match with the actual filename and the second one, PosstgreSQL, was fixed (an extra s in the name)

Also, the linter modified to files so I commited them too.

Tell your future self why have you made these changes
To point to the right file and to have the right database name.

How have you verified this change? Tested locally? Added a unit test? Checked in staging env?
No need to verified this change, it's a readme file

Assuming the worst case, what can be broken when deploying this change to production?
Nothing

Is it notable for release? e.g. schema updates, configuration or data migration required? If so, please mention it, and also update CHANGELOG.md
No

Is there any documentation updates should be made for config, https://cadenceworkflow.io/docs/operation-guide/setup/ ? If so, please open an PR in https://github.com/uber/cadence-docs
No

[CLAassistant]

All committers have signed the CLA.

[longquanzheng]

Thanks for the good catches!

[coveralls]

Pull Request Test Coverage Report for Build 40beddb0-4157-47c5-a477-7cf7687cd3c7

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• 28 unchanged lines in 4 files lost coverage.
• Overall coverage increased (+0.06%) to 67.132%

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Files with Coverage Reduction	New Missed Lines	%
host/signalworkflowTest.go	1	95.53%
service/history/shard/context.go	2	63.06%
common/task/fifoTaskScheduler.go	3	84.54%
common/persistence/cassandra/cassandraTaskPersistence.go	22	59.16%

Totals
Change from base Build a8fd4a2a-a8ba-4e3a-905f-25833e78d216:	0.06%
Covered Lines:	98378
Relevant Lines:	146545

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💛 - Coveralls