docs: Add roadmap section to README

See merge request !1429

Merged-by: Amy Qualls <aqualls@gitlab.com>
Approved-by: Dasha Adushkina <dadushkina@gitlab.com>

chore: Update error message to reflect tier availability

Closes #1263

See merge request gitlab-org/gitlab-vscode-extension!1428

Merged-by: Erran Carey <ecarey@gitlab.com>
Approved-by: Erran Carey <ecarey@gitlab.com>
Co-authored-by: Amy Qualls <aqualls@gitlab.com>

docs: Improve `yalc` link instructions

See merge request gitlab-org/gitlab-vscode-extension!1435

Merged-by: Tomas Vik <tvik@gitlab.com>
Approved-by: Tomas Vik <tvik@gitlab.com>
Co-authored-by: Olena Horal-Koretska <ohoralkoretska@gitlab.com>

fix(chat): Increased timeout for Web View init

Closes #1229

See merge request gitlab-org/gitlab-vscode-extension!1431

Merged-by: Tomas Vik <tvik@gitlab.com>
Approved-by: Tomas Vik <tvik@gitlab.com>
Reviewed-by: Denys Mishunov <dmishunov@gitlab.com>
Co-authored-by: Denys Mishunov <dmishunov@gitlab.com>