README: Add instructions for Llamafile

* README.org (* Llama.cpp): As it turns out, text-generation
Llamafile models (currently Mistral Instruct and Llava) offer an
OpenAI-compatible API, so we can use them easily from gptel.  Add
instructions for Llamafiles to the Llama section of the README.

README.org

@@ -6,12 +6,13 @@ GPTel is a simple Large Language Model chat client for Emacs, with support for m
 
 | LLM Backend | Supports | Requires                  |
 |-------------+----------+---------------------------|
-| ChatGPT     | ✓       | [[https://platform.openai.com/account/api-keys][API key]]                   |
-| Azure       | ✓       | Deployment and API key    |
-| Ollama      | ✓       | [[https://ollama.ai/][Ollama running locally]]    |
-| GPT4All     | ✓       | [[https://gpt4all.io/index.html][GPT4All running locally]]   |
-| Gemini      | ✓       | [[https://makersuite.google.com/app/apikey][API key]]                   |
-| Llama.cpp   | ✓       | [[https://github.com/ggerganov/llama.cpp/tree/master/examples/server#quick-start][Llama.cpp running locally]] |
+| ChatGPT     | ✓      | [[https://platform.openai.com/account/api-keys][API key]]                   |
+| Azure       | ✓      | Deployment and API key    |
+| Ollama      | ✓      | [[https://ollama.ai/][Ollama running locally]]    |
+| GPT4All     | ✓      | [[https://gpt4all.io/index.html][GPT4All running locally]]   |
+| Gemini      | ✓      | [[https://makersuite.google.com/app/apikey][API key]]                   |
+| Llama.cpp   | ✓      | [[https://github.com/ggerganov/llama.cpp/tree/master/examples/server#quick-start][Llama.cpp running locally]] |
+| Llamafile   | ✓      | [[https://github.com/Mozilla-Ocho/llamafile#quickstart][Local Llamafile server]]   |
 | PrivateGPT  | Planned  | -                         |
 
 *General usage*: ([[https://www.youtube.com/watch?v=bsRnh_brggM][YouTube Demo]])
@@ -46,7 +47,7 @@ GPTel uses Curl if available, but falls back to url-retrieve to work without ext
       - [[#gpt4all][GPT4All]]
       - [[#ollama][Ollama]]
       - [[#gemini][Gemini]]
-      - [[#llamacpp][Llama.cpp]]
+      - [[#llamacpp-or-llamafile][Llama.cpp or Llamafile]]
   - [[#usage][Usage]]
     - [[#in-any-buffer][In any buffer:]]
     - [[#in-a-dedicated-chat-buffer][In a dedicated chat buffer:]]
@@ -138,7 +139,7 @@ Register a backend with
 #+end_src
 Refer to the documentation of =gptel-make-azure= to set more parameters.
 
-You can pick this backend from the transient menu when using gptel. (See usage)
+You can pick this backend from the menu when using gptel. (see [[#usage][Usage]])
 
 If you want it to be the default, set it as the default value of =gptel-backend=:
 #+begin_src emacs-lisp
@@ -163,7 +164,7 @@ Register a backend with
 #+end_src
 These are the required parameters, refer to the documentation of =gptel-make-gpt4all= for more.
 
-You can pick this backend from the transient menu when using gptel (see usage), or set this as the default value of =gptel-backend=.  Additionally you may want to increase the response token size since GPT4All uses very short (often truncated) responses by default:
+You can pick this backend from the menu when using gptel (see [[#usage][Usage]]), or set this as the default value of =gptel-backend=.  Additionally you may want to increase the response token size since GPT4All uses very short (often truncated) responses by default:
 
 #+begin_src emacs-lisp
 ;; OPTIONAL configuration
@@ -188,7 +189,7 @@ Register a backend with
 #+end_src
 These are the required parameters, refer to the documentation of =gptel-make-ollama= for more.
 
-You can pick this backend from the transient menu when using gptel (see Usage), or set this as the default value of =gptel-backend=:
+You can pick this backend from the menu when using gptel (see [[#usage][Usage]]), or set this as the default value of =gptel-backend=:
 
 #+begin_src emacs-lisp
 ;; OPTIONAL configuration
@@ -212,7 +213,7 @@ Register a backend with
 #+end_src
 These are the required parameters, refer to the documentation of =gptel-make-gemini= for more.
 
-You can pick this backend from the transient menu when using gptel (see Usage), or set this as the default value of =gptel-backend=:
+You can pick this backend from the menu when using gptel (see [[#usage][Usage]]), or set this as the default value of =gptel-backend=:
 
 #+begin_src emacs-lisp
 ;; OPTIONAL configuration
@@ -224,28 +225,29 @@ You can pick this backend from the transient menu when using gptel (see Usage),
 
 #+html: <details>
 #+html: <summary>
-**** Llama.cpp
+**** Llama.cpp or Llamafile
 #+html: </summary>
 
+(If using a llamafile, run a [[https://github.com/Mozilla-Ocho/llamafile#other-example-llamafiles][server llamafile]] instead of a "command-line llamafile", and a model that supports text generation.)
+
 Register a backend with
 #+begin_src emacs-lisp
 (gptel-make-openai                    ;Not a typo, same API as OpenAI
  "llama-cpp"                          ;Any name
  :stream t                            ;Stream responses
  :protocol "http"
- :host "localhost:8000"               ;Llama.cpp server location
- :models '("test"))                   ;List of available models
+ :host "localhost:8000"               ;Llama.cpp server location, typically localhost:8080 for Llamafile
+ :models '("test"))                   ;Any names, doesn't matter for Llama
 #+end_src
 These are the required parameters, refer to the documentation of =gptel-make-openai= for more.
 
-You can pick this backend from the transient menu when using gptel (see Usage), or set this as the default value of =gptel-backend=:
+You can pick this backend from the menu when using gptel (see [[#usage][Usage]]), or set this as the default value of =gptel-backend=:
 #+begin_src emacs-lisp
 (setq-default gptel-backend (gptel-make-openai "llama-cpp" ...)
               gptel-model   "test")
 #+end_src
 
 #+html: </details>
-
 ** Usage
 
 (This is also a [[https://www.youtube.com/watch?v=bsRnh_brggM][video demo]] showing various uses of gptel.)