Clarify instrumentation definition (open-telemetry#2245)

Co-authored-by: Patrice Chalin <[email protected]>

Author: MattDodsonEnglish

content/en/docs/concepts/instrumenting.md

@@ -6,8 +6,8 @@ description: >-
 weight: 40
 ---
 
-In order to make a system observable, it must be **instrumented**: That is, the
-code must emit
+In order to make a system observable, it must be **instrumented**: That is, code from the
+system's components must emit
 [traces](/docs/concepts/observability-primer/#distributed-traces),
 [metrics](/docs/concepts/observability-primer/#reliability--metrics), and
 [logs](/docs/concepts/observability-primer/#logs).