[Deployment] Setup fly.io deployment method and update docs (#1028)

Co-authored-by: sidmohanty11 <sidmohanty11@gmail.com>

embedchain/deployment/fly.io/app.py

@@ -0,0 +1,53 @@
+from fastapi import FastAPI, responses
+from pydantic import BaseModel
+
+from embedchain import Pipeline
+
+app = FastAPI(title="Embedchain FastAPI App")
+embedchain_app = Pipeline()
+
+
+class SourceModel(BaseModel):
+    source: str
+
+
+class QuestionModel(BaseModel):
+    question: str
+
+
+@app.post("/add")
+async def add_source(source_model: SourceModel):
+    """
+    Adds a new source to the EmbedChain app.
+    Expects a JSON with a "source" key.
+    """
+    source = source_model.source
+    embedchain_app.add(source)
+    return {"message": f"Source '{source}' added successfully."}
+
+
+@app.post("/query")
+async def handle_query(question_model: QuestionModel):
+    """
+    Handles a query to the EmbedChain app.
+    Expects a JSON with a "question" key.
+    """
+    question = question_model.question
+    answer = embedchain_app.query(question)
+    return {"answer": answer}
+
+
+@app.post("/chat")
+async def handle_chat(question_model: QuestionModel):
+    """
+    Handles a chat request to the EmbedChain app.
+    Expects a JSON with a "question" key.
+    """
+    question = question_model.question
+    response = embedchain_app.chat(question)
+    return {"response": response}
+
+
+@app.get("/")
+async def root():
+    return responses.RedirectResponse(url="/docs")