Quick update of ARCHITECTURE.md (#1339)

Author: maciektr

ARCHITECTURE.md

@@ -15,18 +15,24 @@ flowchart TD
     subgraph BUILTIN_CMDS ["Built-in commands"]
         direction LR
         BLD[scarb build]
-        CLN[scarb clean]
+        CHK[scarb check]
+        UPD[scarb update]
+        FTH[scarb fetch]
         FMT[scarb fmt]
-        RUN[scarb run]
+        CLN[scarb clean]
+        CAC[scarb cache]
         NEW[scarb init/new]
         UPD[scarb add/rm/update]
+        PUB[scarb package/publish]
         MET[scarb metadata]
         CMD[scarb commands]
         MAN[scarb manifest-path]
     end
     subgraph EXT_CMDS ["External subcommands system"]
         direction LR
         CAIRO_LS["Cairo Language Server"]
+        CAIRO_RUN["scarb run"]
+        SCARB_DOC["scarb doc"]
         SNFORGE["scarb test\n(can redirect to either snforge,\ncairo-test or other runner)"]
     end
 ```
@@ -74,12 +80,14 @@ classDiagram
         - compilers
     }
     class CairoPluginRepository {
-        - compiler macro plugins
+        - built-in compiler macro plugins
     }
     class StarknetContractCompiler {
     }
     class LibCompiler {
     }
+    class TestCompiler {
+    }
     class Workspace~'c~ {
         + members() Iter~Package~
     }
@@ -107,10 +115,12 @@ classDiagram
         + String name
         + VersionReq
         + SourceId
+        + DepKind
     }
     class Target {
         + TargetKind
         + String name
+        + Optional group_id
         + BTreeMap<String, *> params
     }
     class CompilationUnit {
@@ -144,6 +154,7 @@ classDiagram
     CompilationUnit ..> Target : is created from
     CodegenRepository *-- StarknetContractCompiler 
     CodegenRepository *-- LibCompiler 
+    CodegenRepository *-- TestCompiler 
 ```
 
 ### Sources and the internal registry
@@ -158,15 +169,15 @@ classDiagram
     }
     class PathSource
     class GitSource
-    class StandardLibSource
-    class RegistrySource {
-        <<Future>>
+    class RegistrySource
+    class StandardLibSource {
+        /embedded/
     }
 
     PathSource ..|> Source
     GitSource ..|> Source
-    StandardLibSource ..|> Source
     RegistrySource ..|> Source
+    StandardLibSource ..|> Source
 ```
 
 A _source_ is an object that finds and downloads remote packages based on names and versions.
@@ -176,10 +187,9 @@ There are various `Source` implementation for different methods of downloading p
 1. `PathSource` simply provides an ability to operate on packages from local file system.
 2. `GitSource` downloads packages from Git repositories.
 3. `RegistrySource` downloads packages from package registries.
+4. `StandardLibSource` unpacks packages embedded into the Scarb binary itself.
 4. And more...
 
-**CURRENTLY ONLY PATH AND GIT SOURCES ARE IMPLEMENTED.**
-
 The `Registry` object gathers all `Source` objects in a single mapping, and provides a unified interface for querying
 _any_ package, no matter of its source.
 
@@ -202,9 +212,7 @@ internally.
 
 ### Lockfile
 
-**THIS IS NOT IMPLEMENTED YET.**
-
-      TODO(mkaput): Write this section.
+See Scarb documentation.
 
 ## Scarb Compiler
 
@@ -274,10 +282,11 @@ Plugins appropriate to be used for building a specific package are applied to th
 When using Scarb as a library, Cairo plugins can be defined with configuration builder. 
 If not specified otherwise, Scarb comes with predefined StarkNet Cairo plugin, that can be used for StarkNet contracts
 compilation.
-In the future, Scarb will also provide a way to define Cairo plugins as package dependencies.
 
-**The mechanism for requiring Cairo plugins as package dependencies or compiling them in Scarb runtime is not implemented yet.**
+### Procedural Macros 
 
+Procedural macros provide a mechanism for defining custom macros as package dependencies.
+The package with macro source code definition will be pulled and compiled by Scarb.
 Please see [the design document](design/01-proc-macro.md) for more information.
 
 ### RootDatabase management within the compiler