added h3-section headers to description

src/doc/man/cargo-install.md

@@ -55,6 +55,8 @@ specified by setting the `CARGO_TARGET_DIR` environment variable to a relative
 path. In particular, this can be useful for caching build artifacts on
 continuous integration systems.
 
+### Dealing with the Lockfile
+
 By default, the `Cargo.lock` file that is included with the package will be
 ignored. This means that Cargo will recompute which versions of dependencies
 to use, possibly using newer versions that have been released since the
@@ -69,6 +71,8 @@ not start publishing `Cargo.lock` files until version 1.37, which means
 packages published with prior versions will not have a `Cargo.lock` file
 available.
 
+### Configuration Discovery
+
 This command operates on system or user level, not project level.
 This means that the local [configuration discovery] is ignored.
 Instead, the configuration discovery begins at `$CARGO_HOME/config.toml`. 

src/doc/man/generated_txt/cargo-install.txt

@@ -65,6 +65,7 @@ DESCRIPTION
        variable to a relative path. In particular, this can be useful for
        caching build artifacts on continuous integration systems.
 
+   Dealing with the Lockfile
        By default, the Cargo.lock file that is included with the package will
        be ignored. This means that Cargo will recompute which versions of
        dependencies to use, possibly using newer versions that have been
@@ -79,6 +80,7 @@ DESCRIPTION
        Cargo.lock files until version 1.37, which means packages published with
        prior versions will not have a Cargo.lock file available.
 
+   Configuration Discovery
        This command operates on system or user level, not project level. This
        means that the local configuration discovery
        <https://doc.rust-lang.org/cargo/reference/config.html#hierarchical-structure>

src/doc/src/commands/cargo-install.md

@@ -62,6 +62,8 @@ specified by setting the `CARGO_TARGET_DIR` environment variable to a relative
 path. In particular, this can be useful for caching build artifacts on
 continuous integration systems.
 
+### Dealing with the Lockfile
+
 By default, the `Cargo.lock` file that is included with the package will be
 ignored. This means that Cargo will recompute which versions of dependencies
 to use, possibly using newer versions that have been released since the
@@ -76,6 +78,8 @@ not start publishing `Cargo.lock` files until version 1.37, which means
 packages published with prior versions will not have a `Cargo.lock` file
 available.
 
+### Configuration Discovery
+
 This command operates on system or user level, not project level.
 This means that the local [configuration discovery] is ignored.
 Instead, the configuration discovery begins at `$CARGO_HOME/config.toml`. 

src/etc/man/cargo-install.1

@@ -87,7 +87,7 @@ in a temporary target directory. To avoid this, the target directory can be
 specified by setting the \fBCARGO_TARGET_DIR\fR environment variable to a relative
 path. In particular, this can be useful for caching build artifacts on
 continuous integration systems.
-.sp
+.SS "Dealing with the Lockfile"
 By default, the \fBCargo.lock\fR file that is included with the package will be
 ignored. This means that Cargo will recompute which versions of dependencies
 to use, possibly using newer versions that have been released since the
@@ -101,7 +101,7 @@ will not receive any fixes or updates to any dependency. Note that Cargo did
 not start publishing \fBCargo.lock\fR files until version 1.37, which means
 packages published with prior versions will not have a \fBCargo.lock\fR file
 available.
-.sp
+.SS "Configuration Discovery"
 This command operates on system or user level, not project level.
 This means that the local \fIconfiguration discovery\fR <https://doc.rust\-lang.org/cargo/reference/config.html#hierarchical\-structure> is ignored.
 Instead, the configuration discovery begins at \fB$CARGO_HOME/config.toml\fR\&.