One last fix attempt before I revert everything

Restore unfolding during undo

Avoid stacktrace on undo in 'nomodifiable' buffer

Drop FUNDING.yml in favor of account-level default

Account for Vim undo double-incrementing b:changedtick

Bump minimum Vim version to 8.0

Rework error return to prevent off-by-one in Ex mode

Add sponsor button

Add vim-radical in the plugins list

Make an explicit register on repeat override g:repeat_reg

Documentation fix for repeat#setreg()

feedkeys(..., 'i') sends keys in the wrong order in Vim 7.0/1/2

Remove outdated plugin references

Update installation instructions

Change Markdown heading style