docs: various fixes for grammar, clarity, and consistency across documentation

[sergeypanin1994]

Changes:

1. Updated Twitter URL to x.com format

• Replaced all instances of the outdated Twitter URL (https://twitter.com) with the updated x.com format (https://x.com).
• This aligns with Twitter's rebranding and ensures consistency across documentation.

2. Fixed typos and grammatical errors in the Encrypted Variables section

• Corrected the typo "Lets" → "Let's" in the explanation of data leakage.
• Added a semicolon before "however" to improve sentence structure.
• Fixed an incorrect sentence:
  • "Encrypted card values is the Player and Dealer structs are leaked and can be exploited"
  • Updated to: "Encrypted card values in the Player and Dealer structs are leaked and can be exploited."
• Ensured consistency in explanations regarding encrypted variables.

3. Fixed typos and stylistic errors in the Privacy section

• Changed "Javascript" → "JavaScript" to reflect the correct capitalization of the programming language.
• Added a missing comma before "or" in "events or metadata" for better readability.
• Improved sentence clarity where needed.

4. Grammar, clarity, and consistency improvements in Encryption & Access Control documentation

• Fixed misplaced space in "sealed box encryption ]" → "sealed box encryption".
• Corrected "from NaCL" → "from NaCl" (proper case usage for the cryptographic library).
• Improved clarity and consistency in explanations:
  • "Similarly to decryption, this usage can be implemented by any compliant library, but we include direct support in fhenix.js."
    → "Similar to decryption, this can be implemented by any compliant library, but direct support is included in fhenix.js."
  • "This is done in 3 steps: generating a permit, querying the contract and unsealing the data."
    → "This process involves three steps: generating a permit, querying the contract, and unsealing the data."
• Adjusted wording for gender-neutral phrasing:
  • "the caller is who he says he is." → "the caller is who they claim to be."
• Improved formality and consistency:
  • "Simply, they are a signed message that contains the caller's public key"
  • "Out-of-the-box, Fhenix Solidity libraries come with a basic access control scheme."
    → "The Fhenix Solidity libraries include a built-in access control scheme."

Summary:

• Improved overall readability, correctness, and inclusiveness in the documentation.
• Ensured consistency in terminology, grammar, and formality.
• Reflected up-to-date branding changes (Twitter → X).