Refactor TracerProvider documentation (#3133)

* Refactor TracerProvider documentation

* Fix English article

* Grammar fixes

trace/trace.go

@@ -503,17 +503,48 @@ type Tracer interface {
 	Start(ctx context.Context, spanName string, opts ...SpanStartOption) (context.Context, Span)
 }
 
-// TracerProvider provides access to instrumentation Tracers.
+// TracerProvider provides Tracers that are used by instrumentation code to
+// trace computational workflows.
+//
+// A TracerProvider is the collection destination of all Spans from Tracers it
+// provides, it represents a unique telemetry collection pipeline. How that
+// pipeline is defined, meaning how those Spans are collected, processed, and
+// where they are exported, depends on its implementation. Instrumentation
+// authors do not need to define this implementation, rather just use the
+// provided Tracers to instrument code.
+//
+// Commonly, instrumentation code will accept a TracerProvider implementation
+// at runtime from its users or it can simply use the globally registered one
+// (see https://pkg.go.dev/go.opentelemetry.io/otel#GetTracerProvider).
 //
 // Warning: methods may be added to this interface in minor releases.
 type TracerProvider interface {
-	// Tracer creates an implementation of the Tracer interface.
-	// The instrumentationName must be the name of the library providing
-	// instrumentation. This name may be the same as the instrumented code
-	// only if that code provides built-in instrumentation. If the
-	// instrumentationName is empty, then a implementation defined default
-	// name will be used instead.
+	// Tracer returns a unique Tracer scoped to be used by instrumentation code
+	// to trace computational workflows. The scope and identity of that
+	// instrumentation code is uniquely defined by the name and options passed.
+	//
+	// The passed name needs to uniquely identify instrumentation code.
+	// Therefore, it is recommended that name is the Go package name of the
+	// library providing instrumentation (note: not the code being
+	// instrumented). Instrumentation libraries can have multiple versions,
+	// therefore, the WithInstrumentationVersion option should be used to
+	// distinguish these different codebases. Additionally, instrumentation
+	// libraries may sometimes use traces to communicate different domains of
+	// workflow data (i.e. using spans to communicate workflow events only). If
+	// this is the case, the WithScopeAttributes option should be used to
+	// uniquely identify Tracers that handle the different domains of workflow
+	// data.
+	//
+	// If the same name and options are passed multiple times, the same Tracer
+	// will be returned (it is up to the implementation if this will be the
+	// same underlying instance of that Tracer or not). It is not necessary to
+	// call this multiple times with the same name and options to get an
+	// up-to-date Tracer. All implementations will ensure any TracerProvider
+	// configuration changes are propagated to all provided Tracers.
+	//
+	// If name is empty, then an implementation defined default name will be
+	// used instead.
 	//
-	// This method must be concurrency safe.
-	Tracer(instrumentationName string, opts ...TracerOption) Tracer
+	// This method is safe to call concurrently.
+	Tracer(name string, options ...TracerOption) Tracer
 }