Consistent tier target naming

Author: apiraino

src/compiler/proposals-and-stabilization.md

@@ -254,7 +254,7 @@ circumstance.
   - **Approve using:** r+ (compiler leads)
   - You can `r? compiler_leads` on the PR to roll one of the compiler leads as the reviewer.
   - Open a PR with the new target (w/ relevant documentation updates) and document adherence to the
-    [target tier policy][tier_policy] in the description. New targets must start as tier three
+    [target tier policy][tier_policy] in the description. New targets must start as Tier 3
   - New targets should be assigned to the compiler team co-leads to check for any licensing
     concerns
 - Promoting a target
@@ -264,18 +264,18 @@ circumstance.
     in the description
   - New targets should be assigned to the compiler team co-leads to ensure that any demands on
     the project infrastructure are considered and checked with relevant teams
-- Renaming a target or making a breaking change to a tier three target
+- Renaming a target or making a breaking change to a Tier 3 target
   - **Propose using:** PR
   - **Approve using:** r+
   - Open an PR with the proposed rename and describe the motivation for the change and obtain a r+
     from the reviewer.
-- Renaming a target or making a breaking change to a tier two target
+- Renaming a target or making a breaking change to a Tier 2 target
   - **Propose using:** MCP
   - **Approve using:** FCP
   - Open an MCP describing the motivation for the change and start an FCP to approve, start an FCP.
   - If approved, the change should be accompanied by a blog post announcing the change with a
     notice period of at least one release before the change applies.
-- Renaming a target or making a breaking change to a tier one target
+- Renaming a target or making a breaking change to a Tier 1 target
   - **Propose using:** RFC
   - **Approve using:** FCP
   - Open an RFC describing the motivation for the change and start an FCP to approve, start an FCP.
@@ -286,7 +286,7 @@ circumstance.
   - **Approve using:** FCP
   - Write an MCP describing why the target should be demoted/removed and once discussion has
     concluded, an FCP can be started to approve the demotion/removal.
-  - If approved and affecting a tier two or one target , the change should be accompanied by a
+  - If approved and affecting a Tier 2 or one target, the change should be accompanied by a
     blog post announcing the change with a notice period of at least one release before the change
     applies.
 - Changing target baseline (e.g. minimum Darwin or Windows version bump)

src/infra/other-installation-methods.md

@@ -39,8 +39,8 @@ might one _not_ want to install using those instructions?
 
 Rust's platform support is defined in [three tiers], which correspond closely
 with the installation methods available: in general, the Rust project provides
-binary builds for all tier 1 and tier 2 platforms, and they are all installable
-via `rustup`. Some tier 2 platforms though have only the standard library
+binary builds for all Tier 1 and Tier 2 platforms, and they are all installable
+via `rustup`. Some Tier 2 platforms though have only the standard library
 available, not the compiler itself; that is, they are cross-compilation targets
 only; Rust code can run on those platforms, but they do not run the compiler
 itself. Such targets can be installed with the `rustup target add` command.