Bug 15238: Better translatability for Installer Step 1

 Bug 15238: Better translatability for Installer Step 1

This Bug streamlines html in installer/step1.tt for better translatibility.

To test:
Reviwe code and verify that changes in text make sense.

Signed-off-by: Hector Castro <hector.hecaxmmx@gmail.com>
To reproduce in Debian environment, remove a required module with
dpkg -r. Rewording Ok for translation purposes

Bug 15238: (followup) Remove word 'Note:'

'Note: ' removed as requested in comment #3

Signed-off-by: Hector Castro <hector.hecaxmmx@gmail.com>
Word 'Note' removed

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Brendan A Gallagher <brendan@bywatersolutions.com>