Updating task start/end icons (#51)

* Updating text for task start/end button

  * Previously, the task start/end button directly referenced a "ReachHover"
    task. This is not entirely accurate, since the subject will be using the
    same button to signify the start of both a ReachHover task and a task that
    uses IntelliJ IDEA.

* Updating task button icons

* Updating 1.0.3 -> 1.0.4

gradle.properties

@@ -4,7 +4,7 @@
 pluginGroup = com.github.jyoo980.reachhover
 pluginName = reach-hover
 # SemVer format -> https://semver.org
-pluginVersion = 1.0.3
+pluginVersion = 1.0.4
 
 # See https://plugins.jetbrains.com/docs/intellij/build-number-ranges.html
 # for insight into build numbers and IntelliJ Platform versions.