add release dates to notes

[unitycoder]

like added here https://github.com/UnityCommunity/UnityReleaseNotes/blob/master/5.3%20Patch/5.3.5p4.txt

[hasanbayatme]

@unitycoder Why add release dates to notes when the release dates exists at Unity Official Archive?

[unitycoder]

just to make it easy to find/see, without browsing the archive (could search with release year/date then too..not sure if ever need though)

[hasanbayatme]

Why not using markdown syntax instead of .txt?

[unitycoder]

no time.., but yeah, lost images/links/formatting etc when copied as text only

[hasanbayatme]

We can start from beginning and add release dates from unity 1.0 to latest version.

I am keep going to add release dates and notes, when i am done, i will close this issue.

Thanks.