feat: add first setup screen for LLM & Embedding models (#314) (bump:minor)

* fix: utf-8 txt reader

* fix: revise vectorstore import and make it optional

* feat: add cohere chat model with tool call support

* fix: simplify citation pipeline

* fix: improve citation logic

* fix: improve decompose func call

* fix: revise question rewrite prompt

* fix: revise chat box default placeholder

* fix: add key from ktem to cohere rerank

* fix: conv name suggestion

* fix: ignore default key cohere rerank

* fix: improve test connection UI

* fix: reorder requirements

* feat: add first setup screen

* fix: update requirements

* fix: vectorstore tests

* fix: update cohere version

* fix: relax langchain core version

* fix: add demo mode

* fix: update flowsettings

* fix: typo

* fix: fix bool env passing

flowsettings.py

@@ -24,9 +24,13 @@ if not KH_APP_VERSION:
     except Exception:
         KH_APP_VERSION = "local"
 
+KH_ENABLE_FIRST_SETUP = True
+KH_DEMO_MODE = config("KH_DEMO_MODE", default=False, cast=bool)
+
 # App can be ran from anywhere and it's not trivial to decide where to store app data.
 # So let's use the same directory as the flowsetting.py file.
 KH_APP_DATA_DIR = this_dir / "ktem_app_data"
+KH_APP_DATA_EXISTS = KH_APP_DATA_DIR.exists()
 KH_APP_DATA_DIR.mkdir(parents=True, exist_ok=True)
 
 # User data directory
@@ -59,7 +63,9 @@ os.environ["HF_HUB_CACHE"] = str(KH_APP_DATA_DIR / "huggingface")
 KH_DOC_DIR = this_dir / "docs"
 
 KH_MODE = "dev"
-KH_FEATURE_USER_MANAGEMENT = True
+KH_FEATURE_USER_MANAGEMENT = config(
+    "KH_FEATURE_USER_MANAGEMENT", default=True, cast=bool
+)
 KH_USER_CAN_SEE_PUBLIC = None
 KH_FEATURE_USER_MANAGEMENT_ADMIN = str(
     config("KH_FEATURE_USER_MANAGEMENT_ADMIN", default="admin")
@@ -202,6 +208,14 @@ KH_LLMS["groq"] = {
     },
     "default": False,
 }
+KH_LLMS["cohere"] = {
+    "spec": {
+        "__type__": "kotaemon.llms.chats.LCCohereChat",
+        "model_name": "command-r-plus-08-2024",
+        "api_key": "your-key",
+    },
+    "default": False,
+}
 
 # additional embeddings configurations
 KH_EMBEDDINGS["cohere"] = {