doc: update doc

3.X-migration-guide.md

@@ -1,9 +1,9 @@
 # Overview of changes in 3.X mbedtls
 
 - Update vendor `mbedtls` code from version `2.28.3` to a commit at development version: [0b3de6fce](https://github.com/Mbed-TLS/mbedtls/commit/0b3de6fce)
-  - Please checkout C `mbedtls` migration guide for 3.X here [3.0-migration-guide.md](https://github.com/fortanix/rust-mbedtls/blob/yx/upgrade-mbedtls/mbedtls-sys/vendor/docs/3.0-migration-guide.md) to 
-  - The vendor code at this commit includes the **TLS server side version negotiation** which implements the requirements for [rfc844 4.2.1](https://www.rfc-editor.org/rfc/rfc8446#section-4.2.1)
-  - This is a temporary approach at current time point since upstream has not released major version ( `3.5.0` ) that contains the **Server Side Version Negotiation**, we need to upgrade to `3.5.0` once it's released, its estimated release date is 2023-09-30, Ref: https://github.com/orgs/Mbed-TLS/ 
+  - Please checkout C `mbedtls` [3.0-migration-guide.md](https://github.com/fortanix/rust-mbedtls/blob/yx/upgrade-mbedtls/mbedtls-sys/vendor/docs/3.0-migration-guide.md) for more info
+  - The vendor code at this commit includes the **TLS server side version negotiation** which implements [rfc844 4.2.1](https://www.rfc-editor.org/rfc/rfc8446#section-4.2.1)
+  - This is a temporary approach at current time point since upstream has not released major version ( `3.5.0` ) that contains the **Server Side Version Negotiation**, we need to upgrade to `3.5.0` once it's released, its estimated release date is 2023-09-30, Ref: https://github.com/orgs/Mbed-TLS/
     projects/1#column-19402885
 - Update the build code for `mbedtls-sys-auto` crate to sync up with vendor code change:
   - Changes in C DEFINE's for configuration
@@ -31,7 +31,9 @@
 
 **Upstream changes:**
 
-- :boom: Upgrade vendor `mbeldtls` code to `3.5.0-alpha.1+0b3de6f`, which is at commit in developent branch: [0b3de6fce](https://github.com/Mbed-TLS/mbedtls/commit/0b3de6fce) : this is needed to be able to use a functional complete TLS 1.3 stack implementation. Here I use the pre-release version value since upstream has not release `3.5.0` yet, see: https://doc.rust-lang.org/cargo/reference/semver.html
+- :boom: Upgrade vendor `mbeldtls` code to version `3.5.0-alpha.1+0b3de6f`, it means we are using upstream code at commit [0b3de6fce](https://github.com/Mbed-TLS/mbedtls/commit/0b3de6fce): this is needed because it contains the server side version negotiation features which is necessary in a functional complete TLS 1.3 stack.
+
+Note: Here we use a pre-release version since upstream has not release `3.5.0` yet. Ref: https://doc.rust-lang.org/cargo/reference/semver.html
 
 **Changes on our side:**
 
@@ -118,10 +120,10 @@ Following changes are made according to [3.0-migration-guide.md](https://github.
 - Add prefix `private_` to some fields of `mbedtls` types under `mbedtls/src/cipher/raw`
 - :boom: Removed and added some options in `Error`, `CipherType`, `CipherMode` and `CipherSuite`  to sync with changes in `mbedtls` 3.X
 - :boom: `mbedtls/src/pk/ec.rs` : User need to provide a RNG callback for function `EcPoint::mul`, this originally is not a hard requirement, but in C `mbedtls` 3.X this become a hard requirement for blinding to defend side channel attack.
-- :boom: `mbedtls/hash` : 
+- :boom: `mbedtls/hash` :
   - `Md2` and `Md4` are removed since they are no longer supported in `mbedtls` 3.X
-  - fn `pbkdf_pkcs12` is removed since `pkcs12` is removed 
-- :boom: `mbedtls/pk/mod.rs` : 
+  - fn `pbkdf_pkcs12` is removed since `pkcs12` is removed
+- :boom: `mbedtls/pk/mod.rs` :
   - Remove `CustomPk`
   - User need to provide a RNG callback for `Pk::from_private_key`, this originally is not a hard requirement, but in C `mbedtls` 3.X this become a hard requirement for blinding to defend side channel attack.
 - :boom: `mbedtls/src/ssl/ciphersuites.rs`: Rename `TlsCipherSuite` to `Tls12CipherSuite`, and add enum: `Tls13CipherSuite`, `IanaTlsNamedGroup`, `TLS13SignatureAlgorithms`: these are introduced by TLS 1.3