fix(shell): track the real ~/.bashrc and ~/.gitconfig

The repo copy of .bashrc was a stock Debian startup file that nothing on this
machine reads; the live one is the Arch-style file (interactive guard, color
aliases, vim->nvim, fzf init). Replace it with the live content and start
tracking .gitconfig (identity + nvim as editor/difftool).

.gitconfig

@@ -0,0 +1,7 @@
+[user]
+	email = [email protected]
+	name = Josue Zamudio
+[diff]
+	tool = nvimdiff
+[core]
+	editor = nvim