Fix multiple typos in README.md

[VikramSinghRakwal06]

Corrected the following spelling and grammar errors:

• "student" -> "students" in Tutorial Websites
• "seems" -> "seem" in Tutorial Websites
• "comprehensive" -> "more comprehensive" in Books
• "Alegra" -> "Algebra" in Books for Mathematics
• "byformer" -> "by former" in Books for Mathematics
• "more.." -> "more." in Books for Mathematics
• "It's" -> "it's" in Sites for Practice
• "programing" -> "programming" in Sites for Practice
• "performs" -> "perform" in Tools
• "Palletes" -> "Palettes" in Tools
• "qualtiy" -> "quality" in Community
• "explanined" -> "explained" in Interview Questions