Embed link and YT link validation

[Aniket-508]

Issue that this pull request solves

Closes: #471

Brief description of what is fixed or changed

Made a custom url and yt url regex and then used ternary operator which basically adds the board component if the value entered matched the regex else gives alert to enter a valid url or valid yt url

Types of changes

Put an x in the boxes that apply

• [x] Bugfix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Documentation update (Documentation content changed)
• [ ] Other (please describe):

Checklist

Put an x in the boxes that apply

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] My changes does not break the current system and it passes all the current test cases.

Screenshots

[guardrails[bot]]

:warning: We detected 1 security issue in this pull request:

Insecure Use of Regular Expressions (1)

Docs | Details ----- | -------- [:bulb:](https://docs.guardrails.io/docs/en/vulnerabilities/typescript/insecure_use_of_regular_expressions.html?utm_source=ghpr) | Title: **Regex DOS (ReDOS)**, Severity: Medium
https://github.com/Canvasbird/canvasboard/blob/69f725286ccc8bafa2f2d000c9764702f6917a21/src/app/components/new-board/new-board.component.ts#L1143 More info on how to fix Insecure Use of Regular Expressions in [TypeScript](https://docs.guardrails.io/docs/en/vulnerabilities/typescript/insecure_use_of_regular_expressions.html?utm_source=ghpr).

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[Aniket-508]

@goliakshay357 Please have a look at this.

[goliakshay357]

LGTM!