[Major revision] Review and update descriptions of `<eag>`, `<control>` and its sub-elements

Provide a general summary of the issue in the Title above.

Creator of issue

State your name, organisation and ways to reach you. Name: Kerstin Arnold Organisation: Archives Portal Europe Foundation, Working Group on Standards Email: standards@archivesportaleurope.net GitHub username (if applicable): @kerstarno

Changes to existing element / attribute

Give the current name of the element / attribute. Relates to: <eag>, <control>, <agencyCode>, <agencyName>, <agent>, <citedRange>, <conventionDeclaration>, <date>, <dateRange>, <descriptiveNote>, <eventDateTime>, <eventDescription>, <fromDate>, <languageDeclaration>, <localControl>, <localTypeDeclaration>, <maintenanceAgency>, <maintenanceEvent>, <maintenanceHistory>, <objectXMLWrap>, <otherAgencyCode>, <otherRecordId>, <p>, <recordId>, <reference>, <representation>, <rightsDeclaration>, <shortCode>, <source>, <sources>, <span>, <term>, <toDate>

Link to related schema change issue

Provide the link to the schema change issue for the elements included. Issue: #48,

Changes in text

Summarise all changes required in the tag library with regard to its parts (head, fullName, summary, mayContain, mayOccurWithin, attributes, description, availability, examples). Summary of changes:

See draft EAG 3.0 TEI XML Tag Library at https://github.com/ArchivesPortalEuropeFoundation/EAG2012/blob/MajorRevision_EAG3.0/_draft_EAG3.0_TL_TEI.xml
Check spellings in the head and fullName entries
Check and update summary if necessary (note: for elements inherited from EAC-CPF, the draft Tag Library includes a copy of the EAC-CPF texts that need to be adapted; for elements that already existed in EAG 2012, the draft Tag Library includes a copy of the HTML version of the EAG 2012 texts that need to be updated)
Check mayContain, mayOccurWithin, attributes, and availability against the schema and note any difference (if detected) to confirm whether the schema or the draft Tag Library are correct
Update or create description (note: for elements inherited from EAC-CPF, the draft Tag Library includes a copy of the EAC-CPF texts that need to be adapted; for elements that already existed in EAG 2012, the draft Tag Library might include a slightly extended version of the summary, but this needs to be extended in most cases to highlight specific use cases, to make connections to or distinctions from other elements, to give examples for the usage of certain attributes available with the element being described)
Update of create example encodings (note: for elements inherited from EAC-CPF, the draft Tag Library includes a copy of the EAC-CPF examples that need to be adapted; for elements that already existed in EAG 2012, the draft Tag Library might include an updated encoding example, but most of these examples could either be extended (e.g. to include attributes) or could be supplemented by a second example to show some variations of usage)
- Examples should ideally reflect real use cases of EAG and can either be taken from the complete EAG 3.0 example files or can be snippets created specifically for the use within the Tag Library

ArchivesPortalEuropeFoundation / EAG2012