Adds codeLens.includeSingleLineSymbols setting

Changes changelog image links to permalinks
Moves all images for docs into a docs folder
Removes unused images

Closes #354 - Adds line history explorer (wip)
Closes #456 - Adds repository status to the repository nodes

Renanes "Compare x with" commands

Removes gitlens.advanced.git setting

Changes rebase & reset terminal commands to apply to all commit nodes

Adds clearing of the user cache on config change
Fixes lint issues and adds some comments

Closes #419 - Make blame heatmap color configurable