Changes part about main idea of provider.

As provider is decorated with @Injectable() decorator, it makes more sense that provider can be injected, not that it can inject other dependencies (because, i.e. controllers can do it as well). So, I propose this small change, which can make this part of providers description more clear. Regards.

Author: AvantaR

content/components.md

@@ -1,6 +1,6 @@
 ### Providers
 
-Providers are a fundamental concept in Nest. Many of the basic Nest classes may be treated as a provider – services, repositories, factories, helpers, and so on. The main idea of a provider is that it can **inject** dependencies; this means objects can create various relationships with each other, and the function of "wiring up" instances of objects can largely be delegated to the Nest runtime system.
+Providers are a fundamental concept in Nest. Many of the basic Nest classes may be treated as a provider – services, repositories, factories, helpers, and so on. The main idea of a provider is that it can be **injected** as dependency; this means objects can create various relationships with each other, and the function of "wiring up" instances of objects can largely be delegated to the Nest runtime system.
 
 <figure><img src="/assets/Components_1.png" /></figure>