Set up for Neovim plugins; install NERDTree

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "nerdtree"]
+	path = share/nvim/site/pack/matthewtodd/start/nerdtree
+	url = https://github.com/preservim/nerdtree

README.md

@@ -0,0 +1,42 @@
+## Neovim Plugins
+
+### Adding
+
+```
+# Add the plugin as a submodule in our package.
+git submodule add --name nerdtree \
+  https://github.com/preservim/nerdtree \
+  share/nvim/site/pack/matthewtodd/start/nerdtree
+```
+
+### Tracking a Different Branch
+
+```
+git config -f .gitmodules submodule.nerdtree.branch stable
+```
+
+### Updating
+
+```
+./install
+```
+
+### Removing
+
+```
+# Via https://git-scm.com/docs/gitsubmodules
+#
+# Deleted submodule: A submodule can be deleted by running
+# `git rm <submodule path> && git commit`. This can be undone using git revert.
+#
+# The deletion removes the superproject’s tracking data, which are both the
+# gitlink entry and the section in the .gitmodules file. The submodule’s working
+# directory is removed from the file system, but the Git directory is kept around
+# as it to make it possible to checkout past commits without requiring fetching
+# from another repository.
+#
+# To completely remove a submodule, manually delete `$GIT_DIR/modules/<name>/`.
+
+git rm share/nvim/site/pack/matthewtodd/start/nerdtree
+```
+

etc/git/config

@@ -10,6 +10,9 @@
 [diff]
 	algorithm = patience
 	indentHeuristic = true
+	submodule = log
+[fetch]
+	parallel = 0
 [help]
 	autocorrect = 5
 [init]
@@ -21,6 +24,10 @@
 [rebase]
 	autosquash = true
 	autostash = true
+[status]
+	submodulesummary = 1
+[submodule]
+	recurse = true
 [url "[email protected]:"]
 	insteadOf = https://github.com/
 [user]

etc/nvim/init.vim

@@ -0,0 +1,4 @@
+" keyboard shortcuts
+let mapleader = ','
+nmap <leader>d :NERDTreeToggle<CR>
+nmap <leader>f :NERDTreeFind<CR>

install

@@ -64,6 +64,7 @@ fish -c "BUNDLE_PATH='${XDG_DATA_HOME}/vim' bundle update --gemfile=${DIR}/share
 
 fish -c 'vim +PlugUpgrade +PlugClean +PlugUpdate +qall'
 
+fish -c "git submodule update --init --remote"
 fish -c "mkdir -p '${XDG_DATA_HOME}/nvim'"
 fish -c "ln -sfh ${DIR}/share/nvim/site '${XDG_DATA_HOME}/nvim/site'"