Consistent case in CLI option descriptions

[orhantoy]

I noticed a few inconsistencies in the CLI option descriptions:

$ bin/elasticsearch --help
OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in version 9.0 and will likely be removed in a future release.
starts elasticsearch

Option                Description
------                -----------
-E <KeyValuePair>     Configure a setting
-V, --version         Prints elasticsearch version information and exits
-d, --daemonize       Starts Elasticsearch in the background
-h, --help            show help
-p, --pidfile <Path>  Creates a pid file in the specified path on start
-q, --quiet           Turns off standard output/error streams logging in console
-s, --silent          show minimal output
-v, --verbose         show verbose output

1. Prints elasticsearch [...] vs Starts Elasticsearch [...]
2. Starting with lowercase in show help, show minimal output and show verbose output
3. Also, command description is currently all lowercase: starts elasticsearch

[elasticmachine]

Pinging @elastic/es-core-features (:Core/Features/Features)

[orhantoy]

Noticed that the other CLIs like bin/elasticsearch-setup-passwords, bin/elasticsearch-certgen etc also have inconsistencies. Might be worth looking into those as well.

[elasticmachine]

Pinging @elastic/es-core-infra (:Core/Infra/Core)

[rjernst]

@elasticmachine ok to test

[rjernst]

@elasticmachine update branch

[rjernst]

Thanks for the contribution @orhantoy.