Improve one-page linux install docs

[Ed McDonagh]

From e4fc150166d7eb17afe420c5d1d34ac8 comment from @tcdewit

• mention how to access the orthanc webinterface (localhost:8042)
• think about making the linux configs available inside the distribution, instead of having to copy-paste all the time, would be handy (e.g. openrem-server, gunicorn-openrem.service, celery.conf, celery-openrem.service, openrem_orthanc_config.lua).

[Ed McDonagh]

Adding postgresql client authentication to docs. Refs #651 and #660

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[Ed McDonagh]

Corrected spelling error, added information about Orthanc web interface, made the hostfile example match. Refs #660 [skip ci] docs only

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[Ed McDonagh]

Somehow the endash characters had become mangled. Trying double hyphen. Refs #660 [skip ci] docs only

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[Ed McDonagh]

Double hyphen worked. Fixing another couple. Refs #660 [skip ci] docs only

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[Ed McDonagh]

Second part about sample linux configs can wait till the next release. See #664

[Ed McDonagh]

Adding ref #660 to changes [skip ci] docs only

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[Ed McDonagh]

Merged in issue660improveOnePage (pull request #220)

Fixes #660

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[Luuk]

Adding postgresql client authentication to docs. Refs #651 and #660

→ <<cset c0085a9f6fd2>>

[Luuk]

Corrected spelling error, added information about Orthanc web interface, made the hostfile example match. Refs #660 [skip ci] docs only

→ <<cset fb25ef5e2baf>>

[Luuk]

Somehow the endash characters had become mangled. Trying double hyphen. Refs #660 [skip ci] docs only

→ <<cset 2f3365a72e8a>>

[Luuk]

Double hyphen worked. Fixing another couple. Refs #660 [skip ci] docs only

→ <<cset 285c5ce6d242>>