Feat: minor docs improvements for RLHF and faq on embeddings (#2401) [skip ci]

* feat: add doc on shrink_embeddings and custom calling

* chore: rename inference doc

* fix: clarify same config is used for all cli

* chore: rearrange order inference qmd

* feat: add simpo to doc

* fix: update defaults

* feat: add rl configs to doc

* fix: ensure beta consistent with trl.beta

* fix: clarify about lora/fft

* chore: rename title

* chore: fix language

* feat: move config reference higher

* Update docs/getting-started.qmd

Co-authored-by: salman <salman.mohammadi@outlook.com>

* Update docs/rlhf.qmd

Co-authored-by: salman <salman.mohammadi@outlook.com>

---------

Co-authored-by: salman <salman.mohammadi@outlook.com>

src/axolotl/utils/config/models/input/v0_4_1/__init__.py

@@ -1,4 +1,5 @@
 """Module with Pydantic models for configuration."""
+
 # pylint: disable=too-many-lines
 
 import logging
@@ -1827,6 +1828,14 @@ class AxolotlConfigWCapabilities(AxolotlInputConfig):
                 data["torch_compile"] = False
         return data
 
+    @model_validator(mode="before")
+    @classmethod
+    def check_beta_and_trl_beta_match(cls, data):
+        if data.get("beta") and data.get("trl", {}).get("beta"):
+            if data["beta"] != data["trl"]["beta"]:
+                raise ValueError("beta and trl.beta must match or one must be removed")
+        return data
+
 
 def handle_legacy_message_fields_logic(data: dict) -> dict:
     """