Prepare 0.10.0-rc.1 (#620)

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "lettre"
 # remember to update html_root_url and README.md (Cargo.toml example and deps.rs badge)
-version = "0.10.0-beta.4"
+version = "0.10.0-rc.1"
 description = "Email client"
 readme = "README.md"
 homepage = "https://lettre.rs"

README.md

@@ -28,8 +28,8 @@
 </div>
 
 <div align="center">
-  <a href="https://deps.rs/crate/lettre/0.10.0-beta.4">
-    <img src="https://deps.rs/crate/lettre/0.10.0-beta.4/status.svg"
+  <a href="https://deps.rs/crate/lettre/0.10.0-rc.1">
+    <img src="https://deps.rs/crate/lettre/0.10.0-rc.1/status.svg"
       alt="dependency status" />
   </a>
 </div>
@@ -37,10 +37,15 @@
 ---
 
 **NOTE**: this readme refers to the 0.10 version of lettre, which is
-still being worked on. The master branch and the alpha releases will see
-API breaking changes and some features may be missing or incomplete until
-the stable 0.10.0 release is out.
-Use the [`v0.9.x`](https://github.com/lettre/lettre/tree/v0.9.x) branch for stable releases.
+in release candidate state. Use the [`v0.9.x`](https://github.com/lettre/lettre/tree/v0.9.x)
+branch for the previous stable release.
+
+0.10 is already widely used and is already thought to be more reliable than 0.9, so it should generally be used
+for new projects.
+
+We'd love to hear your feedback about 0.10 design and APIs before final release!
+Start a [discussion](https://github.com/lettre/lettre/discussions) in the repository, whether for
+feedback or if you need help or advice using or upgrading lettre 0.10.
 
 ---
 
@@ -66,7 +71,7 @@ To use this library, add the following to your `Cargo.toml`:
 
 ```toml
 [dependencies]
-lettre = "0.10.0-beta.4"
+lettre = "0.10.0-rc.1"
 ```
 
 ```rust,no_run

src/lib.rs

@@ -95,7 +95,7 @@
 //! [Tokio 1.x]: https://docs.rs/tokio/1
 //! [async-std 1.x]: https://docs.rs/async-std/1
 
-#![doc(html_root_url = "https://docs.rs/crate/lettre/0.10.0-beta.4")]
+#![doc(html_root_url = "https://docs.rs/crate/lettre/0.10.0-rc.1")]
 #![doc(html_favicon_url = "https://lettre.rs/favicon.ico")]
 #![doc(html_logo_url = "https://avatars0.githubusercontent.com/u/15113230?v=4")]
 #![forbid(unsafe_code)]