Fix typos

[Marcofann]

This PR fixes several minor typos across multiple files to improve code readability and maintain consistency in comments and documentation. These changes are purely cosmetic and do not affect functionality.

Files and Changes:

• app/export.go
  • Corrected "a allowed address list" to "an allowed address list."
• app/genesis.go
  • Fixed "key'd by a identifier string" to "key'd by an identifier string."
• x/marketmaker/keeper/marketmaker.go
  • Corrected "by an pair id" to "by a pair id."
• x/marketmaker/keeper/proposal_handler.go
  • Fixed "is not a applied market maker" to "is not an applied market maker."
• x/marketmaker/types/keys.go
  • Corrected "by a address" to "by an address."

[Marcofann]

Hi @crypin, @richard-bachman, @lv-koala

Just a friendly reminder about PR #227: it fixes typos across multiple files in the crescent codebase:

• app/export.go: “a allowed address list” → “an allowed address list.”
• app/genesis.go: “key'd by a identifier string” → “key'd by an identifier string.”
• x/marketmaker/keeper/marketmaker.go: “by an pair id” → “by a pair id.”
• x/marketmaker/keeper/proposal_handler.go: “is not a applied market maker” → “is not an applied market maker.”
• x/marketmaker/types/keys.go: “by a address” → “by an address.”

All checks have passed. This PR is awaiting at least one approving review. Could someone please take a look and approve when you have a moment? Thanks! 🙏