Fixed negative input in Logarithm Calculator

[pankaj-2503]

Fixes Issue🛠️

Closes #630

Description👨‍💻

Added onchange property to call function validateInput() which check if input ==0 or input ==1 then alert this can't be used in log base.Similary number can be only positive.

Type of change📄

function validateInput(){
	var input=document.getElementById('base');
	if(input.value==1 || input.value==0){
		alert("Invalid input log's base can take value between 0 & 1 or positive value except 1");
	}
}

• Bug fix (non-breaking change which fixes an issue)

How this has been tested✅

Locally on my pc

Checklist✅

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added demonstration in the form of GIF/video file
• I am an Open Source Contributor

Screenshots/GIF📷

[netlify]

✅ Deploy Preview for calcdiverse ready!

Name	Link
🔨 Latest commit	ba8739d
🔍 Latest deploy log	https://app.netlify.com/sites/calcdiverse/deploys/663e62f29e9c5200080d7c13
😎 Deploy Preview	https://deploy-preview-660--calcdiverse.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[github-actions]

Hey @pankaj-2503, Welcome to the project CalcDiverse! 🎊
Thanks for your contribution! Your effort makes this project better. Keep it up! 🙌
Please wait for the PR to be reviewed. Happy Coding!! ✨

[Rakesh9100]

Pls don't create PR until you are assigned to an issue @pankaj-2503