Build for only one target for docs.rs (#5427)

* Add docs.rs metadata to all cargo.toml files

* Remove docs.rs metada in substrate's cargo.toml

substrate/frame/support/Cargo.toml

@@ -50,3 +50,6 @@ std = [
 nightly = []
 strict = []
 runtime-benchmarks = []
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]

substrate/frame/support/procedural/Cargo.toml

@@ -16,3 +16,6 @@ frame-support-procedural-tools = { version = "2.0.0-alpha.5", path = "./tools" }
 proc-macro2 = "1.0.6"
 quote = "1.0.3"
 syn = { version = "1.0.7", features = ["full"] }
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]

substrate/frame/support/procedural/tools/Cargo.toml

@@ -14,3 +14,6 @@ proc-macro2 = "1.0.6"
 quote = "1.0.3"
 syn = { version = "1.0.7", features = ["full", "visit"] }
 proc-macro-crate = "0.1.4"
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]

substrate/frame/support/procedural/tools/derive/Cargo.toml

@@ -15,3 +15,6 @@ proc-macro = true
 proc-macro2 = "1.0.6"
 quote = { version = "1.0.3", features = ["proc-macro"] }
 syn = { version = "1.0.7", features = ["proc-macro" ,"full", "extra-traits", "parsing"] }
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]

substrate/frame/support/test/Cargo.toml

@@ -32,3 +32,6 @@ std = [
 	"sp-runtime/std",
 	"sp-state-machine",
 ]
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]