Hardcode 0.0.0-SNAPSHOT as version placeholder

Versions are assigned in CI/CD workflows by -Pversion=${GIT_TAG#v}. This
way version always aligns with Git tags, and for local development, one
can use 0.0.0-SNAPSHOT from maven local for if necessary.

Author: damianmalczewski

README.md

@@ -149,11 +149,20 @@ task. **Note** that **building will fail** if code is not properly formatted.
 ./gradlew spotlessApply
 ```
 
-To publish the built artifacts to local Maven repository, run following command, replacing `XXXX` with the desired
-version. By default, the version is `unspecified` (Gradle's default).
+To publish the built artifacts to local Maven repository, use `publishToMavenLocal` task. It produces artifacts with
+`0.0.0-SNAPSHOT` version placeholder, so they won't conflict with any released versions in your local repository.
 
 ```bash
-./gradlew -Pversion=XXXX publishToMavenLocal
+./gradlew publishToMavenLocal
+```
+
+Note that for using Maven Local artifacts in target projects, you need to add `mavenLocal()` repository.
+
+```kotlin
+repositories {
+    mavenLocal()
+    mavenCentral()
+}
 ```
 
 </details>

gradle.properties

@@ -5,6 +5,7 @@ org.gradle.workers.max=4
 #
 # Project settings
 group=io.github.problem4j
+version=0.0.0-SNAPSHOT
 #
 # Project internal settings
 internal.pom.url=https://github.com/problem4j/problem4j-core