docs(contributing): update contributing docs to mention maxDuration t…

…o 10 (#1734)

* Update docs to mention maxDuration to 10

I forked the project and tried running it, but got an error saying 

The value for maxDuration must be between 1 second and 10 seconds, in order to increase this limit upgrade your plan: https://vercel.com/pricing

- We have to set the maxDuration to 10 for free plans in vercel.json

* docs(contributing.md): improve syntax

Co-authored-by: rickstaa <rick.staa@outlook.com>

CONTRIBUTING.md

@@ -30,13 +30,14 @@ Interested in diving deeper into understanding how github-readme-stats works?
 To run & test github-readme-stats, you need to follow a few simple steps:-
 _(make sure you already have a [Vercel](https://vercel.com/) account)_
 
-1.  Install [Vercel CLI](https://vercel.com/download)
-2.  Fork the repository and clone the code to your local machine
-3.  Run `npm install` in the repository root
-4.  Run the command "vercel" in the root and follow the steps there
-5.  Create a `.env` file in the root of the directory
-6.  In the .env file add a new variable named "PAT_1" with your [GitHub Personal Access Token](https://docs.github.com/en/github/authenticating-to-github/creating-a-personal-access-token)
-7.  Run the command "vercel dev" to start a development server at <https://localhost:3000>
+1.  Install [Vercel CLI](https://vercel.com/download).
+2.  Fork the repository and clone the code to your local machine.
+3.  Run `npm install` in the repository root.
+4.  Run the command "vercel" in the root and follow the steps there.
+5.  Open `vercel.json` and set the maxDuration to 10.
+6.  Create a `.env` file in the root of the directory.
+7.  In the .env file add a new variable named "PAT_1" with your [GitHub Personal Access Token](https://docs.github.com/en/github/authenticating-to-github/creating-a-personal-access-token).
+8.  Run the command "vercel dev" to start a development server at <https://localhost:3000>.
 
 ## Themes Contribution