better docs

website/pages/docs/from-1.5/blocks/build/index.mdx

@@ -12,12 +12,13 @@ sidebar_title: <tt>build</tt>
 
 `@include 'from-1.5/beta-hcl2-note.mdx'`
 
-The `build` block defines what builders are started and what they will do.
+The `build` block defines what builders are started, how to `provision` them
+and if necessary what to do with their artifacts using `post-process`.
 
 `@include 'from-1.5/builds/example-block.mdx'`
 
 
-Define [top-level `source` block](/docs/from-1.5/blocks/source) to configure
+Define [top-level `source` blocks](/docs/from-1.5/blocks/source) to configure
 your builders. The list of available builders can be found in the
 [builders](/docs/builders) section.
 

website/pages/docs/from-1.5/blocks/build/source.mdx

@@ -12,8 +12,8 @@ sidebar_title: <tt>source</tt>
 
 `@include 'from-1.5/beta-hcl2-note.mdx'`
 
-The `source` block in a `build` block allows to use an already defined source
-and to set build fields of a source.
+A `source` block nested in a `build` block allows to use an already defined
+source and to set specific fields.
 
 ```hcl
 # builds.pkr.hcl
@@ -26,5 +26,5 @@ build {
 ```
 
 -> **Note:** If any top-level attribute is re-defined with the same name an
-error will be displayed. In other words you cannot define the `output` field in
+error will be displayed. For example: you cannot define the `output` field in
 the source declaration **and** in the source usage.