Rename for clarity

Servlet did this a while ago and it has been much easier to work with

spec/src/main/asciidoc/expression-language-spec-body.adoc

diff --git a/spec/src/main/asciidoc/ELSpec.adoc b/spec/src/main/asciidoc/expression-language-spec-body.adoc
similarity index 100%
rename from spec/src/main/asciidoc/ELSpec.adoc
rename to spec/src/main/asciidoc/expression-language-spec-body.adoc

spec/src/main/asciidoc/expression-language-spec.adoc

diff --git a/spec/src/main/asciidoc/expression-language-spec.adoc b/spec/src/main/asciidoc/expression-language-spec.adoc
index c89a763..95a8106 100644
--- a/spec/src/main/asciidoc/expression-language-spec.adoc
+++ b/spec/src/main/asciidoc/expression-language-spec.adoc
@@ -1,5 +1,5 @@
 //
-// Copyright (c) 2018, 2024 Contributors to the Eclipse Foundation
+// Copyright (c) 2018, 2025 Contributors to the Eclipse Foundation
 //
 
 = Jakarta Expression Language
@@ -25,4 +25,4 @@
 
 // == Scope
 :sectnums:
-include::ELSpec.adoc[]
+include::expression-language-spec-body.adoc[]