Add g:codeium_tab_fallback documentation (Exafunction#143)

Author: Shougo

autoload/codeium.vim

@@ -37,10 +37,11 @@ function! codeium#CompletionText() abort
 endfunction
 
 function! codeium#Accept() abort
+  let default = get(g:, 'codeium_tab_fallback', pumvisible() ? "\<C-N>" : "\t")
+
   if mode() !~# '^[iR]' || !exists('b:_codeium_completions')
-    return "\t"
+    return default
   endif
-  let default = get(g:, 'codeium_tab_fallback', pumvisible() ? "\<C-N>" : "\t")
 
   let current_completion = s:GetCurrentCompletionItem()
   if current_completion is v:null

doc/codeium.txt

@@ -74,6 +74,13 @@ g:codeium_render        A global boolean flag that controls whether codeium
                         let g:codeium_render = v:false
 <
 
+                                                *g:codeium_tab_fallback*
+g:codeium_tab_fallback  The fallback key when there is no suggestion display
+                        in `codeium#Accept()`.
+>
+                        let g:codeium_tab_fallback = "\t"
+<
+
 MAPS                                            *codeium-maps*
 
                                                 *codeium-i_<Tab>*