Update guides content and code snippets (#80)

# Pull Request Description

## Changes Made
This PR adds updates to the guides:

> `test_it_out.md`
- Fixed outdated code examples

> `add_your_own_tool.md`
- Prepend filename hints to code snippets (for easier navigation)
- Add more code snippets for agent usage and custom tool usage

guides/add_your_own_tool.md

@@ -18,7 +18,7 @@ Extending the **Solana Agent Kit** with custom tools allows you to add specializ
 Create a new TypeScript file in the `src/tools/` directory for your tool (e.g., `custom_tool.ts`).
 
 ### 2. Implement the Tool Class
-
+> `src/langchain/index.ts`
 ```typescript:src/langchain/index.ts
 import { Tool } from "langchain/tools";
 import { SolanaAgentKit } from "../agent";
@@ -51,7 +51,7 @@ export class CustomTool extends Tool {
 ```
 
 ### 3. Add Supporting Functions to SolanaAgentKit
-
+> `src/agent/index.ts`
 ```typescript:src/agent/index.ts
 export class SolanaAgentKit {
   // ... existing code ...
@@ -64,7 +64,7 @@ export class SolanaAgentKit {
 ```
 
 ### 4. Export the Tool
-
+> `src/tools/index.ts`
 ```typescript:src/tools/index.ts
 export * from "./request_faucet_funds";
 export * from "./deploy_token";
@@ -72,7 +72,7 @@ export * from "./custom_tool"; // Add your new tool
 ```
 
 ### 5. Integrate with Agent
-
+> `src/langchain/index.ts`
 ```typescript:src/langchain/index.ts
 import { CustomTool } from "../tools/custom_tool";
 
@@ -104,6 +104,10 @@ if (customTool) {
   const result = await customTool._call("your-input");
   console.log(result);
 }
+
+// or alternatively
+const result = await agent.customFunction("your-input"); // assuming you have a `customFunction` method in SolanaAgentKit
+console.log(result);
 ```
 
 ## Best Practices
@@ -117,7 +121,7 @@ if (customTool) {
 ## Example: Token Price Fetching Tool
 
 Here's a complete example of implementing a tool to fetch token prices:
-
+> `src/tools/fetch_token_price.ts`
 ```typescript:src/tools/fetch_token_price.ts
 import { Tool } from "langchain/tools";
 import { SolanaAgentKit } from "../agent";
@@ -150,7 +154,7 @@ export class FetchTokenPriceTool extends Tool {
 ```
 
 Add the supporting function to SolanaAgentKit:
-
+> `src/agent/index.ts`
 ```typescript:src/agent/index.ts
 export class SolanaAgentKit {
   async getTokenPrice(tokenSymbol: string): Promise<number> {
@@ -170,6 +174,21 @@ export class SolanaAgentKit {
 }
 ```
 
+Then it can be used as such:
+
+```typescript
+import { SolanaAgentKit } from "solana-agent-kit";
+
+const agent = new SolanaAgentKit(
+  "your-wallet-private-key-as-base58",
+  "https://api.mainnet-beta.solana.com",
+  "your-openai-api-key"
+);
+
+const result = await agent.getTokenPrice("SOL");
+console.log(result);
+```
+
 ## Need Help?
 
 If you encounter any issues while implementing your custom tool:

guides/test_it_out.md

@@ -49,12 +49,12 @@ The project includes a test script located at `test/index.ts`. To execute the te
 
 ### Token Deployment
 ```typescript
-import { deploy_token } from "solana-agent-kit";
+import { SolanaAgentKit } from "solana-agent-kit";
 
-const result = await deploy_token(
-  agent,
-  9,                // decimals
-  1000000          // initial supply
+const agent = new SolanaAgentKit("your_private_key");
+
+const result = await agent.deployToken(
+  9, // decimals
 );
 
 console.log("Token Mint Address:", result.mint.toString());
@@ -62,9 +62,11 @@ console.log("Token Mint Address:", result.mint.toString());
 
 ### NFT Collection Creation
 ```typescript
-import { deploy_collection } from "solana-agent-kit";
+import { SolanaAgentKit } from "solana-agent-kit";
 
-const collection = await deploy_collection(agent, {
+const agent = new SolanaAgentKit("your_private_key");
+
+const collection = await agent.deployCollection({
   name: "My NFT Collection",
   uri: "https://arweave.net/metadata.json",
   royaltyBasisPoints: 500,  // 5%