Resolve "Set up papis configuration for reference management"

Add papis config file. Sets up a single 'academia' library in Nextcloud/Library folder.

Uses vim for most editing, and vifm as the file manager. No advanced functionality of papis is touched yet.

The structure of the library is to use authorname-title as subfolders in the library for the individual document clusters (i.e. the info.yaml files and any associated document files or notes).

Will need to further test functionality.

.config/papis/config

@@ -0,0 +1,27 @@
+[settings]
+default-library = academia
+
+opentool = xdg-open
+file-browser = vifm
+
+ref-format = {doc[author_list][0][surname]}{doc[year]}
+
+add-confirm = True
+add-name = {doc[author]}-{doc[title]}
+add-folder-name = {doc[author]}-{doc[title]}
+file-name = {doc[author]}_{doc[year]}_{doc[title]}
+add-file-name = {doc[author]}_{doc[year]}_{doc[title]}
+
+mark-header-format = {mark[value]}: {mark[name]}
+mark-opener-format = zathura --page {mark[value]}
+
+[tui]
+editmode = vi
+options_list.selected_margin_style = bg:ansiwhite fg:ansiblack
+options_list.unselected_margin_style = bg:ansiblack
+
+[test]
+dir = ~/documents/library
+
+[academia]
+dir = ~/Nextcloud/Library/academia