Update 1-05-changes.rst

Updated changelog to use tables to outline changes, etc
Documentation section needs more work/thought
In relation to: https://github.com/IATI/IATI-Guidance/commit/8fb6fb18d05f779b356457857dc5d73aa6a65b42#diff-0ebfb6d2aae9c405a9aa3203cff94affR23
Update 1-05-changes.rst

Updated table formatting
Update 1-05-changes.rst

Edited ``PolicySignificance`` to be non-embedded codelist
Also see: #133
Update 1-05-changes.rst

Added link for discussion on new ``Vocabulary`` code
Update 1-05-changes.rst

Formatting of documentation section
Update 1-05-changes.rst

Latest changes, from bugs spotted by @caprenter: https://github.com/IATI/IATI-Guidance/commit/59ea6e11da8770699a7044c006c7c0361a481c78#commitcomment-7654131
Related Activity code corrected

Copy and paste typo fixed
Merge pull request #135 from IATI/1.05-changelog-SF

1.05 changelog sf