give up on vimwiki

Since there's a broken commit in the history that git fsck does not like

.gitmodules

@@ -126,10 +126,6 @@
 	path = .vim/pack/alpha/start/typescript-vim
 	url = https://github.com/leafgarland/typescript-vim.git
 	shallow = true
-[submodule ".vim/pack/alpha/start/vimwiki"]
-	path = .vim/pack/alpha/start/vimwiki
-	url = https://github.com/vimwiki/vimwiki.git
-	shallow = true
 [submodule "src/faker.alfredworkflow"]
 	path = src/faker.alfredworkflow
 	url = https://github.com/kejadlen/faker.alfredworkflow.git

.vim/pack/alpha/start/vimwiki

@@ -1 +0,0 @@
-Subproject commit 63af6e72dd3fa840bffb3ebcb8c96970c02e0913