nvim/git: Use vimdiff as merge tool & drop DiffConflicts

The conflict markers plugin is what we have been using all the time and
is useful even without resorting to merge tool. Drop the DiffConflicts
plugin and use vimdiff as the merge tool if at all we need to resort to
a full 3 way merge view.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>

git/.gitconfig

@@ -13,9 +13,12 @@
 [http]
 	sslVerify = false
 [merge]
-	tool = diffconflicts
-[mergetool "diffconflicts"]
-	cmd = nvim -c "DiffConflicts" "$MERGED" "$BASE" "$LOCAL" "$REMOTE"
+	tool = vimdiff
+	conflictstyle = diff3
+[mergetool]
+	prompt = false
+[mergetool "vimdiff"]
+	cmd = nvim -d $BASE $LOCAL $REMOTE $MERGED -c '$wincmd w' -c 'wincmd J'
 	trustExitCode = true
 	keepBackup = false
 [commit]

nvim/.config/nvim/init.vim

@@ -22,7 +22,6 @@ Plug 'rhysd/git-messenger.vim'
 Plug 'tpope/vim-fugitive'
 Plug 'airblade/vim-gitgutter'
 Plug 'rhysd/conflict-marker.vim'
-Plug 'whiteinge/diffconflicts'
 Plug 'salcode/vim-interactive-rebase-reverse'
 Plug 'stsewd/fzf-checkout.vim'
 " Boost vim command line mode