chore: Significantly restructure folder layout

This moves the various projects from "type-based" folders (such as
"services" or "tools") into more appropriate semantic folders (such as
"nix", "ops" or "web").

Deprecated projects (nixcon-demo & gotest) which only existed for
testing/demonstration purposes have been removed.

(Note: *all* builds are broken with this commit)

ops/infra/nixos/dotfiles/offlineimaprc

@@ -0,0 +1,39 @@
+[general]
+accounts = tazjin, gmail
+
+[DEFAULT]
+ssl = yes
+sslcacertfile = /etc/ssl/certs/ca-certificates.crt
+
+# Private GMail account (old):
+[Account gmail]
+maxage = 90
+localrepository = gmail-local
+remoterepository = gmail-remote
+synclabels = yes
+
+[Repository gmail-local]
+type = GmailMaildir
+localfolders = ~/mail/gmail
+
+[Repository gmail-remote]
+type = Gmail
+remoteuser = tazjin@gmail.com
+remotepassfile = ~/.config/mail/gmail-pass
+folderfilter = lambda folder: folder == 'INBOX'
+
+# Main private account:
+[Account tazjin]
+localrepository = tazjin-local
+remoterepository = tazjin-remote
+
+[Repository tazjin-local]
+type = Maildir
+localfolders = ~/mail/tazjin
+
+[Repository tazjin-remote]
+type = IMAP
+remotehost = mail.runbox.com
+remoteuser = mail@tazj.in
+remotepassfile = ~/.config/mail/tazjin-pass
+auth_mechanisms = LOGIN