pmt: 2.7.0 changelog update

CHANGELOG.md

@@ -1,12 +1,10 @@
-### Version 2.6.0 Changelog
+### Version 2.7.0 Changelog
 
-    - 'tools.c' cleaned.
-    - Compilation system (make) was subject to a serious update.
-    - Undefined sanitizer added to debug flags.
-    - Dynamic makefiles with separate targets.
-    - Unit was given when the size information was given (M).
-    - use of other compilers from clang was blocked.
+    - Operation support with pipe (|) operator has been added.
+    - Build system has been made dynamic.
+    - Minor changes were made to the layout of bash scripts.
+    - Header names have been changed.
 
 ```
-END OF 2.6.0 UPDATE CHANGELOG
+END OF 2.7.0 UPDATE CHANGELOG
 ```