Use consistent project name variable

Refactor project to use a constant variable for the repository name. This ensures consistency and reduces the risk of errors when referencing the project name in multiple places. Updates were made in settings.gradle.kts, .gitea/template, and Main.kt to use the REPO_NAME variable.

settings.gradle.kts

@@ -1,4 +1,5 @@
 plugins {
   id("org.gradle.toolchains.foojay-resolver-convention") version "0.5.0"
 }
-rootProject.name = "{{.RepoName}}"
+val REPO_NAME = "template"
+rootProject.name = "${REPO_NAME}"