[docs] Add fix-ups to docs/changelog.md

[Brian-M-J]

This PR adds a few typo/grammar fixes to docs/changelog.md:

• Changed "the sequence must be a parameter value and the induction variables are also parameter values in that sequence" to "the sequence and the induction values in the sequence must be parameter values"
• Changed "the inferred passing kind on parameters" to "the inferred parameter convention" (which is more consistent with the term "argument convention" already used by Mojo"
• Changed "specified by the user. This allows users" to "specified by the user. This allows programmers" ("user" was referring to both writers and users of functions)
• Changed "to DType.int32" to "to be DType.int32"
• Changed "treated as owned convention" to "treated according to the owned convention"
• Changed 'This is "worked"' to 'This "worked"'
• Changed "mutated on the body of the function" to "mutated in the body of the function"
• Changed "Added new as_bytes_slice() methods to String and StringLiteral" to "Added a new as_bytes_slice() method to String and StringLiteral"
• Changed "functionalty" to "functionality"
• Changed "method which allow" to "method which allows"
• Changed "ListLiteral and Tuple now only requires" to "ListLiteral and Tuple now only require"