User interface clarifications

[BeritJanssen]

• rewordings / additional amounts of text
• link to Read-IT project website
• add meta info to welcome page so it's search engine discoverable
• short examples of what can be searched
• more entries in menu: "about read-it", "general features", "annotation guidelines", "interface functionalities"

[jgonggrijp]

Specifying "rewordings/additional amounts of text" after a support videocall with some users:

• Rename "Adjust filter" to just "Filter" (nontechnical users found the "adjust" part confusing).
• Make annotation identification in item summary block visually distinct from annotation text snippet (suggestion below).
• Use "contributor" as a preferred label for dc:creator.
• Base category tooltips on a special-purpose property (TODO: find a suitable property, also for @fvignale).
• Edit annotation, which one: explicitly use "choose existing" in the dropdown menu to distinguish it more explicitly from the "create new" option in those scenarios where no existing item has been preselected.
• Edit properties: hide reference to XSD documentation behind an ⓘ icon (in order to not scare off non-techies).
• Edit properties: somehow clarify that you don't need to press the "add" button (which is very prominent) in order to save the properties that were already entered.
• Add a remark somewhere up-front (possibly on the landing page) to acknowledge that annotating with linked data is an inherently complicated domain, that the task can seem a bit daunting because of this and that this is normal (in order to reassure less confident users).

Suggestion for item summary block:

text snippet
Category: item

instead of the current

text snippet or item
(Category)

because users get thrown off when the item summary block seems to suggest that there is a word in the text that isn't actually there. While we're at it, I suggest reducing the text snippet to six words with an ellipsis in the middle, in order to keep the height of each summary block within reasonable bounds.