docs/Changelog: update to reflect latest changes

Update the Changelog page to reflect previous changes and currently open pull-requests. Preview available at: https://ukkopahis.github.io/IOTstack/Updates/Changelog/ Also add Changlog link to the Wiki homepage.

Other contributors are welcome to make change suggestions to the Changelog after creating a pull request.

Using this pull-request to close old resolved/abandoned issues:

Empty / Not actionable
- Closes #374
- Closes #288
- Closes #111
Duplicate of issue mentioned in comment
- Closes #410
- Closes #164
Discussion seems to be over
- Closes #448
- Closes #86
- Closes #47
- Closes #41
No way to reproduce the pi-hole runaway log flood
- Closes #508
User support provided / issue resolved
- Closes #586
- Closes #506
- Closes #504
- Closes #474
- Closes #473
- Closes #434
- Closes #332
- Closes #316
- Closes #305
- Closes #296
- Closes #292
- Closes #234
- Closes #230
- Closes #227
- Closes #204
- Closes #201
- Closes #188
- Closes #177
- Closes #173
- Closes #170
- Closes #161
- Closes #146
- Closes #84
Fixed by upstream
- Closes #495
Supervised/Native Home Assistant support dropped
- Closes #491
- Closes #442
- Closes #225
- Closes #106
- Closes #216
- Closes #214
- Closes #157
Already resolved by another pull request
- Closes #410
- Closes #400
- Closes #385
- Closes #375
- Closes #320
- Closes #307
- Closes #237
- Closes #236
- Closes #210
- Closes #171
- Closes #163
- Closes #114
- Closes #107
- Closes #97
- Closes #55
- Closes #44
Outside the project's scope at this time:
- Closes #96
- Closes #46

Issues reported by Paraphraser to be closable:

SensorsIot / IOTstack