Count file diff by token, not by length of string (#63)

* 1.1.23

* 1.1.24

* feat(package.json): add @dqbd/tiktoken dependency

refactor(generateCommitMessageFromGitDiff.ts): add tokenCount function to count the number of tokens in a string
refactor(generateCommitMessageFromGitDiff.ts): change the way the length of INIT_MESSAGES_PROMPT is calculated to use tokenCount function
refactor(generateCommitMessageFromGitDiff.ts): change the way the length of diff is calculated to use tokenCount function

refactor(generateCommitMessageFromGitDiff.ts): rename function parameter from diff to fileDiff and update function calls accordingly
feat(generateCommitMessageFromGitDiff.ts): add tokenCount function to count tokens in fileDiff and use it to check if fileDiff is bigger than MAX_REQ_TOKENS

feat(utils): add tokenCount function to count the number of tokens in a string
refactor(utils/mergeStrings.ts): use tokenCount function to count the number of tokens in a string instead of checking the length of the concatenated string

---------

Co-authored-by: di-sukharev <dim.sukharev@gmail.com>

package-lock.json

@@ -10,6 +10,7 @@
       "license": "MIT",
       "dependencies": {
         "@clack/prompts": "^0.6.1",
+        "@dqbd/tiktoken": "^1.0.2",
         "axios": "^1.3.4",
         "chalk": "^5.2.0",
         "cleye": "^1.3.2",
@@ -83,6 +84,11 @@
         "node": ">=12"
       }
     },
+    "node_modules/@dqbd/tiktoken": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/@dqbd/tiktoken/-/tiktoken-1.0.2.tgz",
+      "integrity": "sha512-AjGTBRWsMoVmVeN55NLyupyM8TNamOUBl6tj5t/leLDVup3CFGO9tVagNL1jf3GyZLkWZSTmYVbPQ/M2LEcNzw=="
+    },
     "node_modules/@esbuild/android-arm": {
       "version": "0.15.18",
       "resolved": "https://registry.npmjs.org/@esbuild/android-arm/-/android-arm-0.15.18.tgz",