Bug 14919: (follow-up) Fixing some typos and adding to pref description

Bug 14919: (follow-up) Fixing some typos and adding to pref description

- Adds 'holds' to pref description of intranetreadinghistory
- Fixes typo in link to holds history from patron account
- Changes reserve date to hold date in table heading

Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>