feat: documentation site (#1101)

## Description

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- Change 1
- Change 2
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## Testing Performed

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- [ ] I have tested these changes locally and they work as expected.
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- [ ] I have updated the documentation to reflect these changes, if
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<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **Documentation**
- Enhanced project README for clarity and improved environment variables
section.
- Added comprehensive developer and user documentation, including guides
on local development, public API, self-hosting, and compliance
standards.
- Introduced specific guides for contributing, creating API keys, using
webhooks, and setting up security measures.
- Detailed documentation on various fields available for document
signing to improve user understanding.
- Added metadata structuring to improve navigation within the
documentation site.

- **Chores**
  - Updated `.gitignore` to better handle project files.

- **New Features**
- Introduced detailed metadata and documentation for various Documenso
functionalities, including signing documents, user profiles, and
compliance levels.
- Added functionality for Direct Link Signing, enabling easy sharing for
document signing.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Timur Ercan <timur.ercan31@gmail.com>
Co-authored-by: Lucas Smith <me@lucasjamessmith.me>
Co-authored-by: David Nguyen <davidngu28@gmail.com>

README.md

@@ -34,13 +34,9 @@
   <img src="https://github.com/documenso/documenso/assets/13398220/d96ed533-6f34-4a97-be9b-442bdb189c69" style="width: 80%;" />
 </div>
 
-## About this project
+## About Documenso
 
-Signing documents digitally should be fast and easy and should be the best practice for every document signed worldwide.
-
-This is technically quite easy today, but it also introduces a new party to every signature: The signing tool providers. While this is not a problem in itself, it should make us think about how we want these providers of trust to work.
-
-Documenso aims to be the world's most trusted document-signing tool. This trust is built by empowering you to self-host Documenso and review how it works under the hood.
+Signing documents digitally should be fast and easy and should be the best practice for every document signed worldwide. This is technically quite easy today, but it also introduces a new party to every signature: The signing tool providers. While this is not a problem in itself, it should make us think about how we want these providers of trust to work. Documenso aims to be the world's most trusted document-signing tool. This trust is built by empowering you to self-host Documenso and review how it works under the hood.
 
 Join us in creating the next generation of open trust infrastructure.
 
@@ -94,7 +90,7 @@ Contact us if you are interested in our Enterprise plan for large organizations
 - [NextAuth.js](https://next-auth.js.org/) - Authentication
 - [react-email](https://react.email/) - Email Templates
 - [tRPC](https://trpc.io/) - API
-- [@documenso/pdf-sign](https://www.npmjs.com/package/@documenso/pdf-sign) - PDF Signatures
+- [@documenso/pdf-sign](https://www.npmjs.com/package/@documenso/pdf-sign) - PDF Signatures (launching soon)
 - [React-PDF](https://github.com/wojtekmaj/react-pdf) - Viewing PDFs
 - [PDF-Lib](https://github.com/Hopding/pdf-lib) - PDF manipulation
 - [Stripe](https://stripe.com/) - Payments
@@ -243,14 +239,14 @@ cp .env.example .env
 
 The following environment variables must be set:
 
-* `NEXTAUTH_URL`
-* `NEXTAUTH_SECRET`
-* `NEXT_PUBLIC_WEBAPP_URL`
-* `NEXT_PUBLIC_MARKETING_URL`
-* `NEXT_PRIVATE_DATABASE_URL`
-* `NEXT_PRIVATE_DIRECT_DATABASE_URL`
-* `NEXT_PRIVATE_SMTP_FROM_NAME`
-* `NEXT_PRIVATE_SMTP_FROM_ADDRESS`
+- `NEXTAUTH_URL`
+- `NEXTAUTH_SECRET`
+- `NEXT_PUBLIC_WEBAPP_URL`
+- `NEXT_PUBLIC_MARKETING_URL`
+- `NEXT_PRIVATE_DATABASE_URL`
+- `NEXT_PRIVATE_DIRECT_DATABASE_URL`
+- `NEXT_PRIVATE_SMTP_FROM_NAME`
+- `NEXT_PRIVATE_SMTP_FROM_ADDRESS`
 
 > If you are using a reverse proxy in front of Documenso, don't forget to provide the public URL for both `NEXTAUTH_URL` and `NEXT_PUBLIC_WEBAPP_URL` variables!