Change the show_all_buffers option to true by default for buffers picker (#858)

* show_all_buffers true by default, added docs

* [docgen] Update doc/telescope.txt
skip-checks: true

* fix for docs, used param instead of field oops

* [docgen] Update doc/telescope.txt
skip-checks: true

Co-authored-by: Github Actions <actions@github>

lua/telescope/builtin/init.lua

@@ -207,6 +207,9 @@ builtin.reloader = require('telescope.builtin.internal').reloader
 
 --- Lists open buffers in current neovim instance, opens selected buffer on `<cr>`
 ---@param opts table: options to pass to the picker
+---@field show_all_buffers boolean: if true, show all buffers, including unloaded buffers (default true)
+---@field ignore_current_buffer boolean: if true, don't show the current buffer in the list (default false)
+---@field only_cwd boolean: if true, only show buffers in the current working directory (default false)
 builtin.buffers = require('telescope.builtin.internal').buffers
 
 --- Lists available colorschemes and applies them on `<cr>`

lua/telescope/builtin/internal.lua

@@ -563,7 +563,8 @@ internal.buffers = function(opts)
     if 1 ~= vim.fn.buflisted(b) then
         return false
     end
-    if not opts.show_all_buffers and not vim.api.nvim_buf_is_loaded(b) then
+    -- only hide unloaded buffers if opts.show_all_buffers is false, keep them listed if true or nil
+    if opts.show_all_buffers == false and not vim.api.nvim_buf_is_loaded(b) then
       return false
     end
     if opts.ignore_current_buffer and b == vim.api.nvim_get_current_buf() then