nvim: Add mini.ai textobjects from lazyvim

Shamelessly stolen from http://www.lazyvim.org/plugins/coding#miniai,
allows us to select in/around:

[c]lass, [f]unction, [d]igits, MultiCas[e] words, [g]lobal buffer,
[u]sage of functions (function calls) or the last part of a function
[Usage] and the current code bl[o]ck (loop, conditional or block).

Super useful!

nvim/.config/nvim/lua/plugins/base.lua

@@ -210,8 +210,45 @@ return {
 		"echasnovski/mini.nvim",
 		event = { "InsertEnter", "VeryLazy" },
 		config = function()
-			-- manually create lazy loading scenarios
+			local ai = require("mini.ai")
-			require("mini.ai").setup()
+			local function ai_buffer(ai_type)
+				local start_line, end_line = 1, vim.fn.line("$")
+				if ai_type == "i" then
+					-- Skip first and last blank lines for `i` textobject
+					local first_nonblank, last_nonblank = vim.fn.nextnonblank(start_line), vim.fn.prevnonblank(end_line)
+					-- Do nothing for buffer with all blanks
+					if first_nonblank == 0 or last_nonblank == 0 then
+						return { from = { line = start_line, col = 1 } }
+					end
+					start_line, end_line = first_nonblank, last_nonblank
+				end
+
+				local to_col = math.max(vim.fn.getline(end_line):len(), 1)
+				return { from = { line = start_line, col = 1 }, to = { line = end_line, col = to_col } }
+			end
+			ai.setup({
+				custom_textobjects = {
+					c = ai.gen_spec.treesitter({ a = "@class.outer", i = "@class.inner" }), -- class
+					d = { "%f[%d]%d+" }, -- digits
+					e = { -- single part of MultiCaseWords
+						{
+							"%u[%l%d]+%f[^%l%d]",
+							"%f[%S][%l%d]+%f[^%l%d]",
+							"%f[%P][%l%d]+%f[^%l%d]",
+							"^[%l%d]+%f[^%l%d]",
+						},
+						"^().*()$",
+					},
+					f = ai.gen_spec.treesitter({ a = "@function.outer", i = "@function.inner" }), -- function
+					g = ai_buffer, -- buffer with or without whitespace
+					o = ai.gen_spec.treesitter({ -- current 'codeblock'
+						a = { "@block.outer", "@conditional.outer", "@loop.outer" },
+						i = { "@block.inner", "@conditional.inner", "@loop.inner" },
+					}),
+					u = ai.gen_spec.function_call(), -- function [u]sage
+					U = ai.gen_spec.function_call({ name_pattern = "[%w_]" }), -- function [U]sage of last dot element
+				},
+			})
 			-- Align tables and other alignable things
 			require("mini.align").setup({})